WorldWideScience

Sample records for trace gases related

  1. Natural and human-related sources of ozone-forming trace gases in southern Africa

    CSIR Research Space (South Africa)

    Scholes, RJ

    1998-09-01

    Full Text Available or vehicular pollution. The cloud of tropospheric ozone which forms over southern Africa every spring probably has its main origin in natural emissions of the ozone-forming trace gases, including CO from vegetation fires, emissions of NO from soils...

  2. Investigation of size-fractionated urban aerosol and trace gases in Budapest by nuclear-related and other analytical techniques

    International Nuclear Information System (INIS)

    Salma, I.; Maenhaut, W.; Zemplen-Papp, E.; Bobvos, J.

    1998-01-01

    An air pollution study was conducted at two urban residential sites in Budapest (one representing the downtown, the other representing a wooded suburb) from 9 April till 17 May 1996. Size-fractionated aerosol samples were simultaneously collected on a daily basis, and meteorological conditions were recorded at both sampling sites. Stacked filter units (SFUs) with an upper size inlet cut-off were used as sampling device separating the urban aerosol into a coarse (about 10-2 μm equivalent aerodynamic diameter, EAD) and a fine ( 2 , SO 2 , CO and the total mass of the suspended particulate matter were measured every half hour at one of the sampling sites by commercial equipment. The SFU filters were analyzed by gravimetry for the total particle mass, by a light reflectance technique for black carbon, by particle-induced X-ray emission analysis and instrumental neutron activation analysis for elemental composition (in combination for up to 40-45 elements). The analytical results were used for characterizing the levels and the multi-elemental composition of the urban aerosol at both sampling sites and for both size fractions, for investigating the atmospheric concentrations and diurnal variation of some criteria pollutants, and for comparing the time-trends of aerosols and trace gases. Identification of the major source types of the aerosol fractions and trace gases, and assessment of the relative contribution from these sources are to be accomplished by multivariate receptor modeling. The present paper reports on the status of the air pollution study, and gives a discussion of the results

  3. Human activities affecting trace gases and climate

    International Nuclear Information System (INIS)

    Braatz, B.; Ebert, C.

    1990-01-01

    The Earth's climate has been in a constant state of change throughout geologic time due to natural perturbations in the global geobiosphere. However, various human activities have the potential to cause future global warming over a relatively short amount of time. These activities, which affect the Earth's climate by altering the concentrations of trace gases in the atmosphere, include energy consumption, particularly fossil-fuel consumption; industrial processes (production and use of chlorofluorocarbons, halons, and chlorocarbons, landfilling of wastes, and cement manufacture); changes in land use patterns, particularly deforestation and biomass burning; and agricultural practices (waste burning, fertilizer usage, rice production, and animal husbandry). Population growth is an important underlying factor affecting the level of growth in each activity. This paper describes how the human activities listed above contribute to atmospheric change, the current pattern of each activity, and how levels of each activity have changed since the early part of this century

  4. Measurement of Selected Organic Trace Gases During TRACE-P

    Science.gov (United States)

    Atlas, Elliot

    2004-01-01

    Major goals of the TRACE-P mission were: 1) to investigate the chemical composition of radiatively important gases, aerosols, and their precursors in the Asian outflow over the western Pacific, and 2) to describe and understand the chemical evolution of the Asian outflow as it is transported and mixed into the global troposphere. The research performed as part of this proposal addressed these major goals with a study of the organic chemical composition of gases in the TRACE-P region. This work was a close collaboration with the Blake/Rowland research group at UC-Irvine, and they have provided a separate report for their funded effort.

  5. Basic characteristics of atmospheric particles, trace gases and meteorology in a relatively clean Southern African Savannah environment

    Directory of Open Access Journals (Sweden)

    L. Laakso

    2008-08-01

    Full Text Available We have analyzed one year (July 2006–July 2007 of measurement data from a relatively clean background site located in dry savannah in South Africa. The annual-median trace gas concentrations were equal to 0.7 ppb for SO2, 1.4 ppb for NOx, 36 ppb for O3 and 105 ppb for CO. The corresponding PM1, PM2.5 and PM10 concentrations were 9.0, 10.5 and 18.8 μg m−3, and the annual median total particle number concentration in the size range 10–840 nm was 2340 cm−3. During Easterly winds, influence of industrial sources approximately 150 km away from the measurement site was clearly visible, especially in SO2 and NOx concentrations. Of gases, NOx and CO had a clear annual, and SO2, NOx and O3 clear diurnal cycle. Atmospheric new-particle formation was observed to take place in more than 90% of the analyzed days. The days with no new particle formation were cloudy or rainy days. The formation rate of 10 nm particles varied in the range of 0.1–28 cm−3 s−1 (median 1.9 cm−3 s−1 and nucleation mode particle growth rates were in the range 3–21 nm h−1 (median 8.5 nm h−1. Due to high formation and growth rates, observed new particle formation gives a significant contribute to the number of cloud condensation nuclei budget, having a potential to affect the regional climate forcing patterns.

  6. Method for detecting trace impurities in gases

    Science.gov (United States)

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  7. EVALUATION OF SIGNIFICANT ANTHROPOGENIC SOURCES OF RADIATIVELY IMPORTANT TRACE GASES

    Science.gov (United States)

    The report is an initial evaluation of significant anthropogenic sources of radiatively important trace gases. missions of greenhouse gases from human activities--including fossil fuel combustion, industrial/agricultural activities, and transportation--contribute to the increasin...

  8. Atmosphere-Ocean Coupling through Trace Gases

    Science.gov (United States)

    Tegtmeier, S.; Atlas, E. L.; Krüger, K.; Lennartz, S. T.; Marandino, C. A.; Patra, P. K.; Quack, B.; Schlundt, C.

    2017-12-01

    Halogen- and sulfur-containing trace gases, as well as other volatile organic compounds (VOCs, such as isoprene) from biogeochemical marine sources are important constituents of the ocean and the atmosphere. These compounds exert wide-ranging influence on atmospheric chemical processes and climate interactions, as well as on human health in coastal regions. In their reactive form, they can affect the oxidizing capacity of the air and lead to the formation of new particles or the growth of existing ones. In this contribution, marine derived halogen-, sulfur-, and oxygen-containing compounds will be discussed. Their net flux into the atmosphere and their impact on atmospheric processes is analyzed based on observations and model simulations.

  9. Water soluble inorganic trace gases and related aerosol compounds in the tropical boundary layer. An analysis based on real time measurements at a pasture site in the Amazon Basin

    NARCIS (Netherlands)

    Trebs, I.

    2005-01-01

    This dissertation investigates the behavior of water-soluble inorganic trace gases and related aerosol species in the tropical boundary layer. Mixing ratios of ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO;,) and the corresponding water-soluble

  10. Trace Gases, CO2, Climate, and the Greenhouse Effect.

    Science.gov (United States)

    Aubrecht, Gordon J., II

    1988-01-01

    Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

  11. ACTRIS Aerosol, Clouds and Trace Gases Research Infrastructure

    OpenAIRE

    Pappalardo Gelsomina

    2018-01-01

    The Aerosols, Clouds and Trace gases Research Infrastructure (ACTRIS) is a distributed infrastructure dedicated to high-quality observation of aerosols, clouds, trace gases and exploration of their interactions. It will deliver precision data, services and procedures regarding the 4D variability of clouds, short-lived atmospheric species and the physical, optical and chemical properties of aerosols to improve the current capacity to analyse, understand and predict past, current and future evo...

  12. ACTRIS Aerosol, Clouds and Trace Gases Research Infrastructure

    Directory of Open Access Journals (Sweden)

    Pappalardo Gelsomina

    2018-01-01

    Full Text Available The Aerosols, Clouds and Trace gases Research Infrastructure (ACTRIS is a distributed infrastructure dedicated to high-quality observation of aerosols, clouds, trace gases and exploration of their interactions. It will deliver precision data, services and procedures regarding the 4D variability of clouds, short-lived atmospheric species and the physical, optical and chemical properties of aerosols to improve the current capacity to analyse, understand and predict past, current and future evolution of the atmospheric environment.

  13. ACTRIS Aerosol, Clouds and Trace Gases Research Infrastructure

    Science.gov (United States)

    Pappalardo, Gelsomina

    2018-04-01

    The Aerosols, Clouds and Trace gases Research Infrastructure (ACTRIS) is a distributed infrastructure dedicated to high-quality observation of aerosols, clouds, trace gases and exploration of their interactions. It will deliver precision data, services and procedures regarding the 4D variability of clouds, short-lived atmospheric species and the physical, optical and chemical properties of aerosols to improve the current capacity to analyse, understand and predict past, current and future evolution of the atmospheric environment.

  14. Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

    Science.gov (United States)

    Andreae, M. O.; Artaxo, P.; Beck, V.; Bela, M.; Freitas, S.; Gerbig, C.; Longo, K.; Munger, J. W.; Wiedemann, K. T.; Wofsy, S. C.

    2012-07-01

    detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

  15. Our changing atmosphere: Trace gases and the greenhouse effect

    International Nuclear Information System (INIS)

    Rowland, F.S.

    1991-01-01

    A very important factor in the scientific evaluation of greenhouse warming during the last decade has been the realization that this is not just a problem of increasing CO 2 but is rather a more general problem of increasing concentrations of many trace gases. CFCs are increasing at 5% per year with CFC-113 going up at a more rapid rate; methane approximately 1% per year; CO 2 by 0.5% per year; N 2 O about 0.2% per year. These rates of increase have been fed into detailed models of the infrared absorbing characteristics of the atmosphere, and have provided the estimated relative contributions from the various trace gases. Carbon dioxide is still the major contributor to the greenhouse effect, and its yearly contribution appears to be increasing. An important question for dealing with the greenhouse effect will be the full understanding of these CO 2 concentration changes. The total amount of carbon from the burning of fossil fuel that is going into the atmosphere is considerably larger than the carbon dioxide increase registered in the atmosphere. Appreciable CO 2 contributions are also being received from the burning of the tropical forests. The procedures necessary to solve the chlorofluorocarbon problem have been put into place on an international scale and have begun to be implemented. We still have left for the future, however, efforts to reduce emissions of carbon dioxide, methane, and nitrous oxide

  16. Unmanned Aerial Systems for Monitoring Trace Tropospheric Gases

    Directory of Open Access Journals (Sweden)

    Travis J. Schuyler

    2017-10-01

    Full Text Available The emission of greenhouse gases (GHGs has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes <100 m above ground level that can achieve spatiotemporal resolution on the order of meters and seconds. Unmanned aerial systems (UASs can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the most relevant classes of UASs available and evaluates their suitability to operate three kinds of detectors for atmospheric trace gases. The three subsets of UASs discussed are: (1 micro aerial vehicles (MAVs; (2 vertical take-off and landing (VTOL; and, (3 low-altitude short endurance (LASE systems. The trace gas detectors evaluated are first the vertical cavity surface emitting laser (VCSEL, which is an infrared laser-absorption technique; second two types of metal-oxide semiconductor sensors; and, third a modified catalytic type sensor. UASs with wingspans under 3 m that can carry up to 5 kg a few hundred meters high for at least 30 min provide the best cost and convenience compromise for sensors deployment. Future efforts should be focused on the calibration and validation of lightweight analytical systems mounted on UASs for quantifying trace atmospheric gases. In conclusion, UASs offer new and exciting opportunities to study atmospheric composition and its effect on weather patterns and climate change.

  17. Greenhouse effect of trace gases, 1970-1980

    Science.gov (United States)

    Lacis, A.; Hansen, J.; Lee, P.; Lebedeff, S.; Mitchell, T.

    1981-01-01

    Increased abundances were measured for several trace atmospheric gases in the decade 1970-1980. The equilibrium greenhouse warming for the measured increments of CH4, chlorofluorocarbons and N2O is between 50% and 100% of the equilibrium warming for the measured increase of atmospheric CO2 during the same 10 years. The combined warming of CO2 and trace gases should exceed natural global temperature variability in the 1980's and cause the global mean temperature to rise above the maximum of the late 1930's.

  18. Greenhouse effect of chlorofluorocarbons and other trace gases

    Science.gov (United States)

    Hansen, James; Lacis, Andrew; Prather, Michael

    1989-01-01

    A comparison is made of the radiative (greenhouse) forcing of the climate system due to changes of atmospheric chlorofluorocarbons and other trace gases. It is found that CFCs, defined to include chlorofluorocarbons, chlorocarbons, and fluorocarbons, now provide about one-quater of current annual increases in anthropogenic greenhouse climate forcing. If the growth rates of CFC production in the early 1970s had continued to the present, current annual growth of climate forcing due to CFCs would exceed that due to CO2.

  19. Trace gases and other potential perturbations to global climate

    International Nuclear Information System (INIS)

    Wang, W.; Wuebbles, D.J.; Washington, W.M.; Isaacs, R.G.; Molnar, G.

    1986-01-01

    We review the various natural and anthropogenic factors that may affect the climate. The purpose is to summarize our understanding of these factors and their potential future climatic effects so that CO 2 -induced climate change can be viewed in a proper context. The factors we discuss include trace gases, anthropogenic and volcanic aerosols, variation of solar constant, change of surface characteristics, and releases of waste heat. We discuss the origins of the various natural and anthropogenic perturbations, the physical and chemical processes and their interactions, model sensitivity calculations, and model projections of their potential future climatic effects. The discussions center on trace gases because of their potentially large climatic effects. It appears that the increases of atmospheric trace gases of other kinds in addition to CO 2 could have important climatic effects. The model calculations suggest that the combined effect of these other trace gases, and the associated change of atmospheric ozone and water vapor distributions, could potentially warm the climate by an amount comparable in magnitude to the effect of doubling the CO 2 . Aerosols of anthropogenic origins may have substantial effects on regional climate, while the volcanic aerosols may have an effect on large-scale climate for up to a few years after injection. Changes of surface characteristics and releases of waste heat may also have substantial effects on the regional climate, but these effects are most likely to be small when compared with the effect of CO 2 increase. Changes of solar constant could have an effect on the global scale, but the time scale is much longer. There is much more that needs to be learned with regard to the above mentioned natural and anthropogenic factors that may affect the climate. A brief summary of those needs is presented

  20. LIDAR technology for measuring trace gases on Mars and Earth

    Science.gov (United States)

    Riris, H.; Abshire, J. B.; Graham, Allan; Hasselbrack, William; Rodriguez, Mike; Sun, Xiaoli; Weaver, Clark; Mao, Jianping; Kawa, Randy; Li, Steve; Numata, Kenji; Wu, Stewart

    2017-11-01

    Trace gases and their isotopic ratios in planetary atmospheres offer important but subtle clues as to the origins of a planet's atmosphere, hydrology, geology, and potential for biology. An orbiting laser remote sensing instrument is capable of measuring trace gases on a global scale with unprecedented accuracy, and higher spatial resolution that can be obtained by passive instruments. For Earth we have developed laser technique for the remote measurement of the tropospheric CO2, O2, and CH4 concentrations from space. Our goal is to develop a space instrument and mission approach for active CO2 measurements. Our technique uses several on and off-line wavelengths tuned to the CO2 and O2 absorption lines. This exploits the atmospheric pressure broadening of the gas lines to weigh the measurement sensitivity to the atmospheric column below 5 km and maximizes sensitivity to CO2 changes in the boundary layer where variations caused by surface sources and sinks are largest. Simultaneous measurements of O2 column use a selected region in the Oxygen A-band. Laser altimetry and atmospheric backscatter can also be measured simultaneously, which permits determining the surface height and measurements made to thick cloud tops and through aerosol layers. We use the same technique but with a different transmitter at 1.65 um to measure methane concentrations. Methane is also a very important trace gas on earth, and a stronger greenhouse gas than CO2 on a per molecule basis. Accurate, global observations are needed in order to better understand climate change and reduce the uncertainty in the carbon budget. Although carbon dioxide is currently the primary greenhouse gas of interest, methane can have a much larger impact on climate change. Methane levels have remained relatively constant over the last decade but recent observations in the Arctic have indicated that levels may be on the rise due to permafrost thawing. NASA's Decadal Survey underscored the importance of Methane as a

  1. Detections and Sensitive Upper Limits for Methane and Related Trace Gases on Mars during 2003-2014, and planned extensions in 2016

    Science.gov (United States)

    Mumma, Michael J.; Villanueva, Geronimo L.; Novak, Robert E.

    2015-11-01

    Five groups report methane detections on Mars; all results suggest local release and high temporal variability [1-7]. Our team searched for CH4 on many dates and seasons and detected it on several dates [1, 9, 10]. TLS (Curiosity rover) reported methane upper limits [6], and then detections [7] that were consistent in size with earlier reports and that also showed rapid modulation of CH4 abundance.[8] argued that absorption features assigned to Mars 12CH4 by [1] might instead be weak lines of terrestrial 13CH4. If not properly removed, terrestrial 13CH4 signatures would appear on the blue wing of terrestrial 12CH4 even when Mars is red-shifted - but they do not (Fig. S6 of [1]), demonstrating that terrestrial signatures were correctly removed. [9] demonstrated that including the dependence of δ13CH4 with altitude did not affect the residual features, nor did taking δ13CH4 as zero. Were δ13CH4 important, its omission would have overemphasized the depth of 13CH4 terrestrial absorption, introducing emission features in the residual spectra [1]. However, the residual features are seen in absorption, establishing their origin as non-terrestrial - [8] now agrees with this view.We later reported results for multiple organic gases (CH4, CH3OH, H2CO, C2H6, C2H2, C2H4), hydroperoxyl (HO2), three nitriles (N2O, NH3, HCN) and two chlorinated species (HCl, CH3Cl) [9]. Most of these species cannot be detected with current space assets, owing to instrumental limitations (e.g., spectral resolving power). However, the high resolution infrared spectrometers (NOMAD, ACS) on ExoMars 2016 (Trace Gas Orbiter) will begin measurements in late 2016. In solar occultation, TGO sensitivities will far exceed prior capabilities.We published detailed hemispheric maps of H2O and HDO on Mars, inferring the size of a lost early ocean [10]. In 2016, we plan to acquire 3-D spatial maps of HDO and H2O with ALMA, and improved maps of organics with iSHELL/NASA-IRTF.References: [1] Mumma et al. Sci09

  2. Fuel characteristics and trace gases produced through biomass burning

    Directory of Open Access Journals (Sweden)

    BAMBANG HERO SAHARJO

    2010-01-01

    Full Text Available Saharjo BH, Sudo S, Yonemura S, Tsuruta H (2010 Fuel characteristics and trace gases produced through biomass burning. Biodiversitas 11: 40-45. Indonesian 1997/1998 forest fires resulted in forest destruction totally 10 million ha with cost damaged about US$ 10 billion, where more than 1 Gt CO2 has been released during the fire episode and elevating Indonesia to one of the largest polluters of carbon in the world where 22% of world’s carbon dioxide produced. It has been found that 80-90% of the fire comes from estate crops and industrial forest plantation area belongs to the companies which using fire illegally for the land preparation. Because using fire is cheap, easy and quick and also support the companies purpose in achieving yearly planted area target. Forest management and land use practices in Sumatra and Kalimantan have evolved very rapidly over the past three decades. Poor logging practices resulted in large amounts of waste will left in the forest, greatly elevating fire hazard. Failure by the government and concessionaires to protect logged forests and close old logging roads led to and invasion of the forest by agricultural settlers whose land clearances practices increased the risk of fire. Several field experiments had been done in order to know the quality and the quantity of trace produced during biomass burning in peat grass, peat soil and alang-alang grassland located in South Sumatra, Indonesia. Result of research show that different characteristics of fuel burned will have the different level also in trace gasses produced. Peat grass with higher fuel load burned produce more trace gasses compared to alang-alang grassland and peat soil.

  3. Climate-chemical interactions and greenhouse effects of trace gases

    Science.gov (United States)

    Shi, Guang-Yu; Fan, Xiao-Biao

    1994-01-01

    A completely coupled one-dimensional radiative-convective (RC) and photochemical-diffusion (PC) model has been developed recently and used to study the climate-chemical interactions. The importance of radiative-chemical interactions within the troposphere and stratosphere has been examined in some detail. We find that increases of radiatively and/or chemically active trace gases such as CO2, CH4 and N2O have both the direct effects and the indirect effects on climate change by changing the atmospheric O3 profile through their interaction with chemical processes in the atmosphere. It is also found that the climatic effect of ozone depends strongly on its vertical distribution throughout the troposphere and stratosphere, as well on its column amount in the atmosphere.

  4. Sensitivity of RF-driven Plasma Filaments to Trace Gases

    Science.gov (United States)

    Burin, M. J.; Czarnocki, C. J.; Czarnocki, K.; Zweben, S. J.; Zwicker, A.

    2011-10-01

    Filamentary structures have been observed in many types of plasma discharges in both natural (e.g. lightning) and industrial systems (e.g. dielectric barrier discharges). Recent progress has been made in characterizing these structures, though various aspects of their essential physics remain unclear. A common example of this phenomenon can be found within a toy plasma globe (or plasma ball), wherein a primarily neon gas mixture near atmospheric pressure clearly and aesthetically displays filamentation. Recent work has provided the first characterization of these plasma globe filaments [Campanell et al., Physics of Plasmas 2010], where it was noticed that discharges of pure gases tend not to produce filaments. We have extended this initial work to investigate in greater detail the dependence of trace gases on filamentation within a primarily Neon discharge. Our preliminary results using a custom globe apparatus will be presented, along with some discussion of voltage dependencies. Newly supported by the NSF/DOE Partnership in Basic Plasma Science and Engineering.

  5. Long-Term Changes of Tropospheric Trace Gases over Pakistan Derived From Multiple Satellite Instruments

    Science.gov (United States)

    Zeb, Naila; Fahim Khokhar, Muhammad; Murtaza, Rabbia; Noreen, Asma; Khalid, Tameem

    2016-07-01

    Air pollution is the expected key environmental issue of Pakistan in coming years due to its ongoing rapid economic growth and this trend suggests only worst air quality over time. In 2014, World bank reported the Pakistan's urban air quality among the most severe in the world and intimated the government to make improvement in air quality as a priority policy agenda. In addition it is recommended to strengthen the institutional and technical capacity of organizations responsible for air quality management. Therefore, the study is designed to put efforts in highlighting air quality issues. The study will provide first database for tropospheric trace gases over Pakistan. The study aims to analyse tropospheric concentrations of CO, TOC, NO2 and HCHO over Pakistan using multisensory data from January 2005 to January 2014. Spatio-temporal and seasonal variability of tropospheric trace gases is observed over the decade to explore long term trend. Hotspots are identified to see variation of species with latitude and to highlight possible sources of trace gases over the Pakistan. High concentrations of trace gases are mainly observed over the Punjab region, which may be attributed to its metropolitan importance. It is the major agricultural, industrialized and urbanized (nearly 60% of the Pakistan's population) sector of the country. Overall significant decreasing trend of CO is identified by MOPITT with relative change of 12.4%. Tropospheric ozone column (TOC) showed insignificant increasing trend with temporal increase of 10.4% whereas NO2 exhibited a significant temporal increase of about 28%. For formaldehyde (HCHO), an increase of about 3.8% is calculated for SCIAMACHY data. Well defined seasonal cycles for these trace gases are observed over the whole study period. CO concentrations showed peak in winter months (November/December/January/February) and dip in the months of Summer/Monsoon (June/July/August). In spite of CO, TCO increases gradually in March and peaks

  6. Trace gases over Northern Eurasia: background level and disturbing factors

    Science.gov (United States)

    Skorokhod, A.; Shumsky, R.; Pankratova, N.; Moiseenko, K.; Vasileva, A.; Berezina, E.; Elansky, N.

    2012-04-01

    not exceed 1 ppb that is typical for background areas but may vary by order and some more in few hours. Higher surface NOx(=NO+NO2) concentrations during day time generally correspond to higher ozone when NO/NO2 ratio indicates on clean or slightly polluted conditions. If there are carbonaceous admixtures (, methane, VOC, etc.) in atmospheric air during the daytime, the NO level more than 10 - 20 ppb is enough for organic matter chain reactions, which lead to ozone accumulation in the atmosphere, to occur. There are almost no such conditions in the rural Siberia. Despite the prevailing western transport higher ozone (as well as other trace gases) concentrations are correlated with air of southern origin. Anthropogenic pollutants like NOx and CO come to Central Siberia mostly from industrial regions of Southern Siberia. Intrusions from China are not typical because of blocking Asian anticyclone. After analysis of surface ozone concentrations one may conclude that climatic conditions (light, temperature, wind conditions, etc.) and chemical composition of the main polluting components (NO, NO2, CO, methane, etc.) do not help (with rare exceptions) the active generation of ozone in the atmospheric air over Siberia. Nocturnal O3 dry deposition and soil emissions of CO2, CH4 were estimated for different parts of Siberia from radon measurements in TROICA experiments. The impact of wildfires on surface air composition over central Siberia is investigated based on near-surface carbon monoxide (CO) measurements conducted at ZOTTO during 2007 and 2008 warm seasons. Seasonal variations of intensity and spatial distribution of wildfires in south of western and eastern Siberia are found to be important factors contributing a substantial part of synoptic and year-to-year variability of background CO levels in the region. The estimated relative CO enhancement in fire plumes with transport times up to 2 days is about 5-25 ppb in springs 2007 and 2008, and 50 ppb in summer 2008, based

  7. An investigation of the sub-grid variability of trace gases and aerosols for global climate modeling

    Directory of Open Access Journals (Sweden)

    Y. Qian

    2010-07-01

    Full Text Available One fundamental property and limitation of grid based models is their inability to identify spatial details smaller than the grid cell size. While decades of work have gone into developing sub-grid treatments for clouds and land surface processes in climate models, the quantitative understanding of sub-grid processes and variability for aerosols and their precursors is much poorer. In this study, WRF-Chem is used to simulate the trace gases and aerosols over central Mexico during the 2006 MILAGRO field campaign, with multiple spatial resolutions and emission/terrain scenarios. Our analysis focuses on quantifying the sub-grid variability (SGV of trace gases and aerosols within a typical global climate model grid cell, i.e. 75×75 km2.

    Our results suggest that a simulation with 3-km horizontal grid spacing adequately reproduces the overall transport and mixing of trace gases and aerosols downwind of Mexico City, while 75-km horizontal grid spacing is insufficient to represent local emission and terrain-induced flows along the mountain ridge, subsequently affecting the transport and mixing of plumes from nearby sources. Therefore, the coarse model grid cell average may not correctly represent aerosol properties measured over polluted areas. Probability density functions (PDFs for trace gases and aerosols show that secondary trace gases and aerosols, such as O3, sulfate, ammonium, and nitrate, are more likely to have a relatively uniform probability distribution (i.e. smaller SGV over a narrow range of concentration values. Mostly inert and long-lived trace gases and aerosols, such as CO and BC, are more likely to have broad and skewed distributions (i.e. larger SGV over polluted regions. Over remote areas, all trace gases and aerosols are more uniformly distributed compared to polluted areas. Both CO and O3 SGV vertical profiles are nearly constant within the PBL during daytime, indicating that trace gases

  8. Tracking Oxidation During Transport of Trace Gases in Air from the Northern to Southern Hemisphere

    Science.gov (United States)

    Montzka, S. A.; Moore, F. L.; Atlas, E. L.; Parrish, D. D.; Miller, B. R.; Sweeney, C.; McKain, K.; Hall, B. D.; Siso, C.; Crotwell, M.; Hintsa, E. J.; Elkins, J. W.; Blake, D. R.; Barletta, B.; Meinardi, S.; Claxton, T.; Hossaini, R.

    2017-12-01

    Trace gas mole fractions contain the imprint of recent influences on an air mass such as sources, transport, and oxidation. Covariations among the many gases measured from flasks during ATom and HIPPO, and from the ongoing NOAA cooperative air sampling program enable recent influences to be identified from a wide range of sources including industrial activity, biomass burning, emissions from wetlands, and uptake by terrestrial ecosystems. In this work we explore the evolution of trace gas concentrations owing to atmospheric oxidation as air masses pass through the tropics, the atmospheric region with the highest concentrations of the hydroxyl radical. Variations in C2-C5 hydrocarbon concentrations downwind of source regions provide a measure of photochemical ageing in an air mass since emission, but they become less useful when tracking photochemical ageing as air is transported from the NH into the SH owing to their low mixing ratios, lifetimes that are very short relative to transport times, non-industrial sources in the tropics (e.g., biomass burning), and southern hemispheric sources. Instead, we consider a range of trace gases and trace gas pairs that provide a measure of photochemical processing as air transits the tropics. To be useful in this analysis, these trace gases would have lifetimes comparable to interhemispheric transport times, emissions arising from only the NH at constant relative magnitudes, and concentrations sufficient to allow precise and accurate measurements in both hemispheres. Some anthropogenically-emitted chlorinated hydrocarbons meet these requirements and have been measured during ATom, HIPPO, and from NOAA's ongoing surface sampling efforts. Consideration of these results and their implications for tracking photochemical processing in air as it is transported across the tropics will be presented.

  9. Ultrasensitive detection of atmospheric trace gases using frequency modulation spectroscopy

    Science.gov (United States)

    Cooper, David E.

    1986-01-01

    Frequency modulation (FM) spectroscopy is a new technique that promises to significantly extend the state-of-the-art in point detection of atmospheric trace gases. FM spectroscopy is essentially a balanced bridge optical heterodyne approach in which a small optical absorption or dispersion from an atomic or molecular species of interest generates an easily detected radio frequency (RF) signal. This signal can be monitored using standard RF signal processing techniques and is, in principle, limited only by the shot noise generated in the photodetector by the laser source employed. The use of very high modulation frequencies which exceed the spectral width of the probed absorption line distinguishes this technique from the well-known derivative spectroscopy which makes use of low (kHz) modulation frequencies. FM spectroscopy was recently extended to the 10 micron infrared (IR) spectral region where numerous polyatomic molecules exhibit characteristic vibrational-rotational bands. In conjunction with tunable semiconductor diode lasers, the quantum-noise-limited sensitivity of the technique should allow for the detection of absorptions as small as .00000001 in the IR spectral region. This sensitivity would allow for the detection of H2O2 at concentrations as low as 1 pptv with an integration time of 10 seconds.

  10. Long Term Association of Tropospheric Trace gases over Pakistan by exploiting satellite observations and development of Econometric Regression based Model

    Science.gov (United States)

    Zeb, Naila; Fahim Khokhar, Muhammad; Khan, Saud Ahmed; Noreen, Asma; Murtaza, Rabbia

    2017-04-01

    . Furthermore to explore causal relation, regression analysis is employed to estimate model for CO and TOC. This model numerically estimated the long term association of trace gases over the region.

  11. Pilot Institute on Global Change on Trace Gases and the Biosphere, 1988

    Science.gov (United States)

    Eddy, J. A.; Moore, B.

    1998-01-01

    Table of Contents: Summary; Background; General Framework for a Series of Institutes on Global Change; The 1988 Pilot Institute on Global Changes: Trace Gases and the Biosphere; Budget; List of Acronyms; and Attachments.

  12. MIRAGE: Model description and evaluation of aerosols and trace gases

    Science.gov (United States)

    Easter, Richard C.; Ghan, Steven J.; Zhang, Yang; Saylor, Rick D.; Chapman, Elaine G.; Laulainen, Nels S.; Abdul-Razzak, Hayder; Leung, L. Ruby; Bian, Xindi; Zaveri, Rahul A.

    2004-10-01

    The Model for Integrated Research on Atmospheric Global Exchanges (MIRAGE) modeling system, designed to study the impacts of anthropogenic aerosols on the global environment, is described. MIRAGE consists of a chemical transport model coupled online with a global climate model. The chemical transport model simulates trace gases, aerosol number, and aerosol chemical component mass (sulfate, methane sulfonic acid (MSA), organic matter, black carbon (BC), sea salt, and mineral dust) for four aerosol modes (Aitken, accumulation, coarse sea salt, and coarse mineral dust) using the modal aerosol dynamics approach. Cloud-phase and interstitial aerosol are predicted separately. The climate model, based on Community Climate Model, Version 2 (CCM2), has physically based treatments of aerosol direct and indirect forcing. Stratiform cloud water and droplet number are simulated using a bulk microphysics parameterization that includes aerosol activation. Aerosol and trace gas species simulated by MIRAGE are presented and evaluated using surface and aircraft measurements. Surface-level SO2 in North American and European source regions is higher than observed. SO2 above the boundary layer is in better agreement with observations, and surface-level SO2 at marine locations is somewhat lower than observed. Comparison with other models suggests insufficient SO2 dry deposition; increasing the deposition velocity improves simulated SO2. Surface-level sulfate in North American and European source regions is in good agreement with observations, although the seasonal cycle in Europe is stronger than observed. Surface-level sulfate at high-latitude and marine locations, and sulfate above the boundary layer, are higher than observed. This is attributed primarily to insufficient wet removal; increasing the wet removal improves simulated sulfate at remote locations and aloft. Because of the high sulfate bias, radiative forcing estimates for anthropogenic sulfur given in 2001 by S. J. Ghan and

  13. The broad-band overlap problem in atmospheric trace gases

    International Nuclear Information System (INIS)

    Subasilar, B.

    1991-01-01

    In relation to a better understanding of climate change and the related greenhouse problem, one way of projecting for the next decades is through general circulation models (GCMs). The only input as a driving force in the changing atmospheric and oceanic circulation patterns is the amount of heat perturbation either due to natural or man-caused activities. Among these, CO 2 concentrations resulting from the latter has been observed to be accelerating at alarmingly high rates especially after the advent of the industrialization which just began in the last century. In addition to that, collective effects of other greenhouse gases (freons, SO 2 , H 2 O, CH 4 , etc.) are as important as CO 2 . Hence, it is evident from the above considerations that, in the predictions of climate models, the heat input which triggers changes in the atmospheric patterns, should be formulated accurately. In order to realize this objective, in this research, beginning with the available line parameter data, the problems of absorption have been investigated and attacked in the frame known as the broad band modeling since that is the only best and fastest manageable representation for GCMs. The first step was the construction of a full broad band (intra band overlap) model that was also flexible enough to accommodate the individual peculiarities of the bands. Before, the well known and very useful Ramanathan model had a limited applicability in the concentration scale, and it was also not systematically or successfully incorporated into an inter band overlap picture. Then, the established ideas that served as bases up to present, have been employed but found to have a limited practical applicability when it came to predict the inter band overlaps

  14. Adsorption of trace gases to ice surfaces: surface, bulk and co-adsorbate effects

    Science.gov (United States)

    Kerbrat, Michael; Bartels-Rausch, Thorsten; Huthwelker, Thomas; Schneebeli, Martin; Pinzer, Bernd; Ammann, Markus

    2010-05-01

    Atmospheric ices frequently interact with trace gases and aerosol making them an important storage, transport or reaction medium in the global ecosystem. Further, this also alters the physical properties of the ice particles with potential consequences for the global irradiation balance and for the relative humidity of surrounding air masses. We present recent results from a set of laboratory experiments of atmospheric relevance to investigate the nature of the uptake processes. The focus of this talk will be placed on the partitioning of acidic acid and nitrous acid on ice surfaces.The presented results span from very simple reversible adsorption experiments of a single trace gas onto ice surfaces to more complex, but well controlled, experimental procedures that successfully allowed us to - Disentangle surface adsorption and uptake into the ice matrix using radioactive labelled trace gases. - Show that simultaneous adsorption of acetic acid and nitrous acid to an ice surface is consistent with the Langmuir co-adsorption model. The experiments were done in a packed ice bed flow tube at atmospheric pressure and at temperatures between 213 and 253 K. The HONO gas phase mixing ratio was between 0.4 and 137 ppbv, the mixing ratio of acetic acid between 5 and 160 ppbv . The use of the radioactive labelled nitrous acid molecules for these experiments enabled in situ monitoring of the migration of trace gas in the flow tube. The measurements showed that the interactions do not only occur through adsorption but also via diffusion into polycrystalline ice. A method is suggested to disentangle the bulk and the surface processes. The co-adsorption of acetic and nitrous acids was also investigated. The measurements are well reproduced by a competitive Langmuir adsorption model.

  15. Tracing enhanced oil recovery signatures in casing gases from the Lost Hills oil field using noble gases

    Science.gov (United States)

    Barry, Peter H.; Kulongoski, Justin; Landon, Matthew K.; Tyne, R.L.; Gillespie, Janice; Stephens, Michael; Hillegonds, D.J.; Byrne, D.J.; Ballentine, C.J.

    2018-01-01

    Enhanced oil recovery (EOR) and hydraulic fracturing practices are commonly used methods to improve hydrocarbon extraction efficiency; however the environmental impacts of such practices remain poorly understood. EOR is particularly prevalent in oil fields throughout California where water resources are in high demand and disposal of high volumes of produced water may affect groundwater quality. Consequently, it is essential to better understand the fate of injected (EOR) fluids in California and other subsurface petroleum systems, as well as any potential effect on nearby aquifer systems. Noble gases can be used as tracers to understand hydrocarbon generation, migration, and storage conditions, as well as the relative proportions of oil and water present in the subsurface. In addition, a noble gas signature diagnostic of injected (EOR) fluids can be readily identified. We report noble gas isotope and concentration data in casing gases from oil production wells in the Lost Hills oil field, northwest of Bakersfield, California, and injectate gas data from the Fruitvale oil field, located within the city of Bakersfield. Casing and injectate gas data are used to: 1) establish pristine hydrocarbon noble-gas signatures and the processes controlling noble gas distributions, 2) characterize the noble gas signature of injectate fluids, 3) trace injectate fluids in the subsurface, and 4) construct a model to estimate EOR efficiency. Noble gas results range from pristine to significantly modified by EOR, and can be best explained using a solubility exchange model between oil and connate/formation fluids, followed by gas exsolution upon production. This model is sensitive to oil-water interaction during hydrocarbon expulsion, migration, and storage at reservoir conditions, as well as any subsequent modification by EOR.

  16. Greenhouse effects due to man-made perturbations of trace gases

    Science.gov (United States)

    Wang, W. C.; Yung, Y. L.; Lacis, A. A.; Mo, T.; Hansen, J. E.

    1976-01-01

    Nitrous oxide, methane, ammonia, and a number of other trace constituents of the earth's atmosphere have infrared absorption bands in the spectral range from 7 to 14 microns. Despite their small amounts, these gases can have a significant effect on the thermal structure of the atmosphere by transmitting most of the thermal radiation from the earth's surface to the lower atmosphere. In the present paper, this greenhouse effect is computed for a number of trace gases. The nature and climatic implications of possible changes in the concentrations of N2O, CH4, NH3, and HNO3 are discussed.

  17. Measurements of Long-Lived Trace Gases from Commercial Aircraft Platforms: Development of Instrumentation

    Science.gov (United States)

    2002-01-01

    The upper troposphere (6-12 km altitude) is a poorly understood and highly vulnerable region of the atmosphere. It is important because many trace species, including ozone, have their greatest impact as greenhouse (infrared-absorbing) gases in this region. The addition of relatively small amounts of anthropogenic chemicals, such as nitrogen oxides, can have a dramatic effect on the abundance of ozone. Some of these pollutants are deposited directly, e.g., by aircraft, while others are transported in. The primary goal of this project was to measure several chemical compounds in the upper troposphere that will help us to understand how air is to transported to that part of the atmosphere; that is, does it come down from the stratosphere, does it rise from the surface via convection, and so on. To obtain adequate sampling to accomplish this goal, we proposed to make measurements from revenue aircraft during normal flight operations.

  18. Adsorption and Detection of Hazardous Trace Gases by Metal-Organic Frameworks.

    Science.gov (United States)

    Woellner, Michelle; Hausdorf, Steffen; Klein, Nicole; Mueller, Philipp; Smith, Martin W; Kaskel, Stefan

    2018-06-19

    The quest for advanced designer adsorbents for air filtration and monitoring hazardous trace gases has recently been more and more driven by the need to ensure clean air in indoor, outdoor, and industrial environments. How to increase safety with regard to personal protection in the event of hazardous gas exposure is a critical question for an ever-growing population spending most of their lifetime indoors, but is also crucial for the chemical industry in order to protect future generations of employees from potential hazards. Metal-organic frameworks (MOFs) are already quite advanced and promising in terms of capacity and specific affinity to overcome limitations of current adsorbent materials for trace and toxic gas adsorption. Due to their advantageous features (e.g., high specific surface area, catalytic activity, tailorable pore sizes, structural diversity, and range of chemical and physical properties), MOFs offer a high potential as adsorbents for air filtration and monitoring of hazardous trace gases. Three advanced topics are considered here, in applying MOFs for selective adsorption: (i) toxic gas adsorption toward filtration for respiratory protection as well as indoor and cabin air, (ii) enrichment of hazardous gases using MOFs, and (iii) MOFs as sensors for toxic trace gases and explosives. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Inter-hemispheric gradient of atmospheric trace gases in the Pacific

    International Nuclear Information System (INIS)

    Lowe, D.; Manning, M.; Brailsford, G.; Bromley, T.; Moss, R.; Ferretti, D.

    1997-01-01

    Measurements of atmospheric trace gases show that the concentrations and isotopic compositions of these species can change dramatically across the intertropical convergence zone (ITCZ) separating the two hemispheres. Because the anthropogenic sources of virtually all trace gases are greater in the northern than in the southern hemisphere, concentrations of the species are lower in the southern hemisphere. Typically the concentration gradient is inversely proportional to the lifetime of the trace gas in the atmosphere. Hence understanding the transport across the ITCZ is crucial to determining the variation of important trace gases in the New Zealand region. Container ships are being used to collect large clean air samples on voyages across the Pacific on great circle routes between Auckland (New Zealand), Honolulu (Hawaii) and Los Angeles and Seattle on the US West coast. Measurements on these samples are being used to supplement extensive carbon isotope measurements of atmospheric methane made at fixed sites in the southern hemisphere: Baring Head (New Zealand), Suva (Fiji) and Scott Base (Antarctica) to provide information on the global methane cycle. The authors present the first results of high precision measurements of the stable isotopes of atmospheric carbon monoxide and methane in transects across the equator. These have been obtained using a Finnigan MAT 252 high precision isotope ratio mass spectrometer with a modified miniature inlet system and a stringent calibration protocol. Overall precision for δ 13 C in ambient methane and carbon monoxide in clean air approaches 0.02 per thousand which helps provide information on several subtle processes controlling the abundance of the trace gases in the atmosphere. The 13 C in methane and carbon dioxide data show remarkable seasonal variations across the intertropical convergence zone (ITCZ) and may be used to infer aspects of transport of gases to extra tropical regions in the southern hemisphere

  20. 1988 Pilot Institute on Global Change on trace gases and the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, J.A.; Moore, B. III

    1998-07-01

    This proposal seeks multi-agency funding to conduct an international, multidisciplinary 1988 Pilot Institute on Global Change to take place from August 7 through 21, 1988, on the topic: Trace Gases and the Biosphere. The institute, to be held in Snowmass, Colorado, is envisioned as a pilot version of a continuing series of institutes on Global Change (IGC). This proposal seeks support for the 1988 pilot institute only. The concept and structure for the continuing series, and the definition of the 1988 pilot institute, were developed at an intensive and multidisciplinary Summer Institute Planning Meeting in Boulder, Colorado, on August 24--25, 1987. The theme for the 1988 PIGC, Trace Gases and the Biosphere, will focus a concerted, high-level multidisciplinary effort on a scientific problem central to the Global Change Program. Dramatic year-to-year increases in the global concentrations of radiatively-active trace gases such as methane and carbon dioxide are now well documented. The predicted climatic effects of these changes lend special urgency to efforts to study the biospheric sources and sinks of these gases and to clarify their interactions and role in the geosphere-biosphere system.

  1. Trace substances in landfill gases. Evaluation and meaningful analysis. Spurenstoffe in Deponiegasen. Bewertung und sinnvolle Analyse

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, R [Karlsruhe Univ. (T.H.) (Germany, F.R.). Engler-Bunte-Institut

    1989-06-01

    Many of the innumerable substances which may occur in landfill gases are to be considered as possibly dangerous; they lead to environmental problems due to their malodour or noxious combustion products. With respect to the evaluation of the traces of substances there is great unsecurity and often extreme requirements as to volume and quality of gas analyses have to be met. Generally it can be noticed that there are hazards emanating from landfill gases, but in comparison to other risks they are not excessive. The contribution shall help to clarify questions and furnish a basis for the practice-oriented and appropriate landfill gas analytics. (orig.).

  2. Techniques for the measurement of trace moisture in high-purity electronic specialty gases

    International Nuclear Information System (INIS)

    Funke, Hans H.; Grissom, Brad L.; McGrew, Clark E.; Raynor, Mark W.

    2003-01-01

    The control of water vapor (moisture) contamination in process gases is critical to the successful manufacture of semiconductor devices. As specified moisture levels have become more stringent, there is a growing demand for more sensitive analytical methods. Instrumental methods currently being used or in development for measuring trace moisture at ppbv levels include Fourier transform infrared spectroscopy, tunable diode laser absorption spectroscopy, cavity ringdown spectroscopy, intracavity laser spectroscopy, electron impact ionization mass spectrometry, and atmospheric pressure ionization mass spectrometry. In addition, sensor-based technologies such as oscillating quartz crystal microbalances, and chilled mirror-, capacitor-, and electrolytic-based hygrometers operate in this regime. These approaches are presented and reviewed. As the success of each trace moisture method is dependent on the degree to which the different process gases interfere with the measurement process, important process gas applications of the techniques are highlighted. Advantages and disadvantages as well as future developments and trends are also presented

  3. Opo lidar sounding of trace atmospheric gases in the 3 - 4 μm spectral range

    Science.gov (United States)

    Romanovskii, Oleg A.; Sadovnikov, Sergey A.; Kharchenko, Olga V.; Yakovlev, Semen V.

    2018-04-01

    The applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO) generation to lidar sounding of the atmosphere in the spectral range 3-4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases (TAG) is based on differential absorption lidar (DIAL) method and differential optical absorption spectroscopy (DOAS). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases. The numerical simulation performed shows that a KTA-based OPO laser is a promising source of radiation for remote DIAL-DOAS sounding of the TAGs under study along surface tropospheric paths. A possibility of using a PD38-03-PR photodiode for the DIAL gas analysis of the atmosphere is shown.

  4. Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes

    Science.gov (United States)

    Megonigal, J. P.; Hines, M. E.; Visscher, P. T.

    2003-12-01

    's surface area, they have a profound influence on the biogeochemistry of the planet. This is evident from the observation that the O2 and CH4 content of Earth's atmosphere are in extreme disequilibrium (Sagan et al., 1993). The combination of high aerobic primary production and anoxic sediments provided the large deposits of fossil fuels that have become vital and contentious sources of energy for modern industrialized societies. Anaerobic metabolism is responsible for the abundance of N2 in the atmosphere; otherwise N2-fixing bacteria would have consumed most of the N2 pool long ago (Schlesinger, 1997). Anaerobic microorganisms are common symbionts of termites, cattle, and many other animals, where they aid digestion. Nutrient and pollutant chemistry are strongly modified by the reduced conditions that prevail in wetland and aquatic ecosystems.This review of anaerobic metabolism emphasizes aerobic oxidation, because the two processes cannot be separated in a complete treatment of the topic. It is process oriented and highlights the fascinating microorganisms that mediate anaerobic biogeochemistry. We begin this review with a brief discussion of CO2 assimilation by autotrophs, the source of most of the reducing power on Earth, and then consider the biological processes that harness this potential energy. Energy liberation begins with the decomposition of organic macromolecules to relatively simple compounds, which are simplified further by fermentation. Methanogenesis is considered next because CH4 is a product of acetate fermentation, and thus completes the catabolism of organic matter, particularly in the absence of inorganic electron acceptors. Finally, the organisms that use nitrogen, manganese, iron, and sulfur for terminal electron acceptors are considered in order of decreasing free-energy yield of the reactions.

  5. Assessment of TRACE Condensation Model Against Reflux Condensation Tests with Noncondensable Gases

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Won; Cheong, Ae Ju; Shin, Andong; Suh, Nam Duk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    The TRACE is the latest in a series of advanced, best-estimated reactor systems code developed by U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. This special model is expected to replace the default model in a future code release after sufficient testing has been completed. This study assesses the special condensation model of TRACE 5.0-patch4 against the counter-current flow configuration. For this purpose, the predicted results of special model are compared to the experimental and to those of default model. The KAST reflux condensation test with NC gases are used in this assessment. We assessed the special model for film condensation of TRACE 5.0-patch4 against the data of the reflux condensation test in the presence of NC gases. The special condensation model of TRACE provides a reasonable estimate of HTC with good agreement at the low inlet steam flow rate.

  6. Assessment of TRACE Condensation Model Against Reflux Condensation Tests with Noncondensable Gases

    International Nuclear Information System (INIS)

    Lee, Kyung Won; Cheong, Ae Ju; Shin, Andong; Suh, Nam Duk

    2015-01-01

    The TRACE is the latest in a series of advanced, best-estimated reactor systems code developed by U.S. Nuclear Regulatory Commission for analyzing transient and steady-state neutronic-thermal-hydraulic behavior in light water reactors. This special model is expected to replace the default model in a future code release after sufficient testing has been completed. This study assesses the special condensation model of TRACE 5.0-patch4 against the counter-current flow configuration. For this purpose, the predicted results of special model are compared to the experimental and to those of default model. The KAST reflux condensation test with NC gases are used in this assessment. We assessed the special model for film condensation of TRACE 5.0-patch4 against the data of the reflux condensation test in the presence of NC gases. The special condensation model of TRACE provides a reasonable estimate of HTC with good agreement at the low inlet steam flow rate

  7. Climate-chemical interactions and effects of changing atmospheric trace gases

    Science.gov (United States)

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.

    1987-01-01

    The paper considers trace gas-climate effects including the greenhouse effect of polyatomic trace gases, the nature of the radiative-chemical interactions, and radiative-dynamical interactions in the stratosphere, and the role of these effects in governing stratospheric climate change. Special consideration is given to recent developments in the investigations of the role of oceans in governing the transient climate responses, and a time-dependent estimate of the potential trace gas warming from the preindustrial era to the early 21st century. The importance of interacting modeling and observational efforts is emphasized. One of the problems remaining on the observational front is the lack of certainty in current estimates of the rate of growth of CO, O3, and NOx; the primary challenge is the design of a strategy that will minimize the sampling errors.

  8. Climate-chemical interactions and effects of changing atmospheric trace gases

    International Nuclear Information System (INIS)

    Ramanathan, V.; Callis, L.; Cess, R.; Hansen, J.; Isaksen, I.; Lacis, A.; Kuhn, W.; Luther, F.; Mahlman, J.; Reck, R.; Schlesinger, M.

    1992-01-01

    The problem concerning the greenhouse effects of human activities has broadened in scope from the CO 2 -climate problem to the trace gas-climate problem. The climate effects of non-CO 2 trace gases are strongly governed by interactions between chemistry, radiation, and dynamics. The authors discuss in detail the nature of the trace gas radiative heating and describe the importance of radiative-chemical interactions within the troposphere and the stratosphere. They make an assessment of the trace gas effects on troposphere-stratosphere temperature trends for the period covering the preindustrial era to the present and for the next several decades. Non-CO 2 greenhouse gases in the atmosphere are now adding to the greenhouse effect by an amount comparable to the effect of CO 2 . The rate of decadal increase of the total greenhouse forcing is now 3-6 times greater than the mean rate for the period 1850-1960. Time-dependent calculations with a simplified one-dimensional diffusive ocean model suggest that a surface warming about 0.4-0.8 K should have occurred during 1850 to 1980. For the various trace gas scenarios considered in this study, the equilibrium surface warming for the period 1980 to 2030 ranges from 0.8 to 4.1 K. This wide range in the projected warming is due to the range in the assumed scenario as well as due to the threefold uncertainty in the sensitivity of climate models. For the 180-year period from 1850 to 2030, their analysis suggests a trace gas-induced cumulative equilibrium surface warming in the range of 1.5 to 6.1 K

  9. Trace water vapor determination in nitrogen and corrosive gases using infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, L.H.; Niemczyk, T.M. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemistry; Stallard, B.R.; Garcia, M.J. [Sandia National Labs., Albuquerque, NM (United States)

    1997-06-01

    The generation of particles in gas handling systems as a result of corrosion is a major concern in the microelectronics industry. The corrosion can be caused by the presence of trace quantities of water in corrosive gases such as HCl or HBr. FTIR spectroscopy has been shown to be a method that can be made compatible with corrosive gases and is capable of detecting low ppb levels of water vapor. In this report, the application of FTIR spectroscopy combined with classical least squares multivariate calibration to detect trace H{sub 2}O in N{sub 2}, HCl and HBr is discussed. Chapter 2 discusses the gas handling system and instrumentation required to handle corrosive gases. A method of generating a background spectrum useful to the measurements discussed in this report, as well as in other application areas such as gas phase environmental monitoring, is discussed in Chapter 3. Experimental results obtained with the first system are presented in Chapter 4. Those results made it possible to optimize the design options for the construction of a dedicate system for low ppb water vapor determination. These designs options are discussed in Chapter 5. An FTIR prototype accessory was built. In addition, a commercially available evacuable FTIR system was obtained for evaluation. Test results obtained with both systems are discussed in Chapter 6. Experiments dealing with the interaction between H{sub 2}O-HCl and potential improvements to the detection system are discussed in Chapter 7.

  10. Recent trends in the variability of halogenated trace gases over the United States

    Science.gov (United States)

    Hurst, Dale F.; Bakwin, Peter S.; Elkins, James W.

    1998-10-01

    Recent trends in the atmospheric variability of seven halogenated trace gases are determined from three years (November 1994 through October 1997) of hourly gas chromatographic measurements at a 610 m tower in North Carolina and 17 months (June 1996 through October 1997) of similar measurements at a 450 m tower in Wisconsin. Production of five of these gases, CCl3F (CFC-11), CCl2F2 (CFC-12), CCl2FCClF2 (CFC-113), CH3CCl3 (methyl chloroform), and CCl4 (carbon tetrachloride), is now strictly regulated in the United States and other developed countries under international legislation. C2Cl4 (tetrachloroethene) and SF6 (sulfur hexafluoride) are currently produced without restriction, but requests for voluntary cutbacks in C2Cl4 emissions have been made, at least in the United States. Atmospheric variability of these gases is examined at several sampling heights on the towers, but trends are deduced using only nighttime data at the top sampling level of each tower to minimize variability driven by local emissions and the diurnal cycle of the planetary boundary layer, leaving regional emissions as the main source of day-to-day variability. Significant downward trends are determined for CFC-12, CFC-113, CH3CCl3, and C2Cl4 variability at both towers, reflecting decreased emissions of these gases in two regions of the United States. Trends in CFC-11, CCl4, and SF6 variability at both towers are not significantly different from zero.

  11. Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams.

    Science.gov (United States)

    Coutts, Janelle L.; Lunn, Griffin Michael; Meyer, Caitlin E.

    2015-01-01

    In membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center's sub-scale MABRs, as well as Johnson Space Center's full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need

  12. Potential for the use of reconstructed IASI radiances in the detection of atmospheric trace gases

    Directory of Open Access Journals (Sweden)

    N. C. Atkinson

    2010-07-01

    Full Text Available Principal component (PC analysis has received considerable attention as a technique for the extraction of meteorological signals from hyperspectral infra-red sounders such as the Infrared Atmospheric Sounding Interferometer (IASI and the Atmospheric Infrared Sounder (AIRS. In addition to achieving substantial bit-volume reductions for dissemination purposes, the technique can also be used to generate reconstructed radiances in which random instrument noise has been reduced. Studies on PC analysis of hyperspectral infrared sounder data have been undertaken in the context of numerical weather prediction, instrument monitoring and geophysical variable retrieval, as well as data compression. This study examines the potential of PC analysis for chemistry applications.

    A major concern in the use of PC analysis for chemistry is that the spectral features associated with trace gases may not be well represented in the reconstructed spectra, either due to deficiencies in the training set or due to the limited number of PC scores used in the radiance reconstruction. In this paper we show examples of reconstructed IASI radiances for several trace gases: ammonia, sulphur dioxide, methane and carbon monoxide. It is shown that care must be taken in the selection of spectra for the initial training set: an iterative technique, in which outlier spectra are added to a base training set, gives the best results. For the four trace gases examined, key features of the chemical signatures are retained in the reconstructed radiances, whilst achieving a substantial reduction in instrument noise.

    A new regional re-transmission service for IASI is scheduled to start in 2010, as part of the EUMETSAT Advanced Retransmission Service (EARS. For this EARS-IASI service it is intended to include PC scores as part of the data stream. The paper describes the generation of the reference eigenvectors for this new service.

  13. Trace gases and CO sub(2) isotope records from Cabo de Rama, India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, S.K.; Borole, D.V.; Francey, R.J.; Allison, C.E.; Steele, L.P.; Krummel, P.; Langenfelds, R.; Masarie, K.A.; Tiwari, Y.K.; Patra, P.K.

    to avoid dan- gerous climate change due to GHG forced warming. Con- centrations of CO 2 , CH 4 and N 2 O have increased at alarming rates, from preindustrial values of 280 ppm, 715 ppb and 270 ppb (circa. 1750) to 379 ppm, 1732 ppb and 319 ppb... an important effect on the con- centration and isotopic composition of atmospheric CO 2 , and the concentrations of other trace gases. Air sampling at CRI contributes to the global atmospheric composition study 10,11 . Given the potential for global impacts...

  14. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: FY 1993 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Stoss, F.W. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment, and Resources Center

    1994-01-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provide technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC (including World Data Center-A for Atmospheric Trace Gases) during the period October 1, 1992, to September 30, 1993. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of NDPS, CMPS, technical reports, newsletters, fact sheets, specialty publications, and reprints are provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also presented.

  15. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: FY 1993 activities

    International Nuclear Information System (INIS)

    Cushman, R.M.; Stoss, F.W.; Univ. of Tennessee, Knoxville, TN

    1994-01-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provide technical responses to specific inquiries related to carbon dioxide (CO 2 ), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC (including World Data Center-A for Atmospheric Trace Gases) during the period October 1, 1992, to September 30, 1993. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of NDPS, CMPS, technical reports, newsletters, fact sheets, specialty publications, and reprints are provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also presented

  16. Characterization of atmospheric trace gases and particulate matter in Hangzhou, China

    Science.gov (United States)

    Zhang, Gen; Xu, Honghui; Qi, Bing; Du, Rongguang; Gui, Ke; Wang, Hongli; Jiang, Wanting; Liang, Linlin; Xu, Wanyun

    2018-02-01

    The Yangtze River Delta (YRD) is one of the most densely populated regions in China with severe air quality issues that have not been fully understood. Thus, in this study, based on 1-year (2013) continuous measurement at a National Reference Climatological Station (NRCS, 30.22° N, 120.17° E; 41.7 m a.s.l.) in the center of Hangzhou in the YRD, we investigated the seasonal characteristics, interspecies relationships, and the local emissions and the regional potential source contributions of trace gases (including O3, NOx, NOy, SO2, and CO) and particulate matter (PM2.5 and PM10). Results revealed that severe two-tier air pollution (photochemical and haze pollution) occurred in this region, with frequent exceedances in O3 (38 days) and PM2.5 (62 days). O3 and PM2.5 both exhibited distinct seasonal variations with reversed patterns: O3 reaching a maximum in warm seasons (May and July) but PM2.5 reaching a maximum in cold seasons (November to January). The overall results from interspecies correlation indicated a strong local photochemistry favoring the O3 production under a volatile organic compound (VOC)-limited regime, whereas it moved towards an optimum O3 production zone during warm seasons, accompanied by the formation of secondary fine particulates under high O3. The emission maps of PM2.5, CO, NOx, and SO2 demonstrated that local emissions were significant for these species on a seasonal scale. The contributions from the regional transport among inland cities (Zhejiang, Jiangsu, Anhui, and Jiangxi Province) on a seasonal scale were further confirmed to be crucial to air pollution at the NRCS site by using backward trajectory simulations. Air masses transported from the offshore areas of the Yellow Sea, East Sea, and South Sea were also found to be highly relevant to the elevated O3 at the NRCS site through the analysis of potential source contribution function (PSCF). Case studies of photochemical pollution (O3) and haze (PM2.5) episodes both suggested the

  17. Characteristics of Fine Particles in an Urban Atmosphere—Relationships with Meteorological Parameters and Trace Gases

    Science.gov (United States)

    Zhang, Tianhao; Zhu, Zhongmin; Gong, Wei; Xiang, Hao; Fang, Ruimin

    2016-01-01

    Atmospheric fine particles (diameter industrial emissions. To reveal the characteristics of fine particles in an industrial city of a developing country, two-year measurements of particle number size distribution (15.1 nm–661 nm), meteorological parameters, and trace gases were made in the city of Wuhan located in central China from June 2012 to May 2014. The annual average particle number concentrations in the nucleation mode (15.1 nm–30 nm), Aitken mode (30 nm–100 nm), and accumulation mode (100 nm–661 nm) reached 4923 cm−3, 12193 cm−3 and 4801 cm−3, respectively. Based on Pearson coefficients between particle number concentrations and meteorological parameters, precipitation and temperature both had significantly negative relationships with particle number concentrations, whereas atmospheric pressure was positively correlated with the particle number concentrations. The diurnal variation of number concentration in nucleation mode particles correlated closely with photochemical processes in all four seasons. At the same time, distinct growth of particles from nucleation mode to Aitken mode was only found in spring, summer, and autumn. The two peaks of Aitken mode and accumulation mode particles in morning and evening corresponded obviously to traffic exhaust emissions peaks. A phenomenon of “repeated, short-lived” nucleation events have been created to explain the durability of high particle concentrations, which was instigated by exogenous pollutants, during winter in a case analysis of Wuhan. Measurements of hourly trace gases and segmental meteorological factors were applied as proxies for complex chemical reactions and dense industrial activities. The results of this study offer reasonable estimations of particle impacts and provide references for emissions control strategies in industrial cities of developing countries. PMID:27517948

  18. Towards uncertainty estimates in global operational forecasts of trace gases in the Copernicus Atmosphere Monitoring System

    Science.gov (United States)

    Huijnen, V.; Bouarar, I.; Chabrillat, S. H.; Christophe, Y.; Thierno, D.; Karydis, V.; Marecal, V.; Pozzer, A.; Flemming, J.

    2017-12-01

    Operational atmospheric composition analyses and forecasts such as developed in the Copernicus Atmosphere Monitoring Service (CAMS) rely on modules describing emissions, chemical conversion, transport and removal processing, as well as data assimilation methods. The CAMS forecasts can be used to drive regional air quality models across the world. Critical analyses of uncertainties in any of these processes are continuously needed to advance the quality of such systems on a global scale, ranging from the surface up to the stratosphere. With regard to the atmospheric chemistry to describe the fate of trace gases, the operational system currently relies on a modified version of the CB05 chemistry scheme for the troposphere combined with the Cariolle scheme to describe stratospheric ozone, as integrated in ECMWF's Integrated Forecasting System (IFS). It is further constrained by assimilation of satellite observations of CO, O3 and NO2. As part of CAMS we have recently developed three fully independent schemes to describe the chemical conversion throughout the atmosphere. These parameterizations originate from parent model codes in MOZART, MOCAGE and a combination of TM5/BASCOE. In this contribution we evaluate the correspondence and elemental differences in the performance of the three schemes in an otherwise identical model configuration (excluding data-assimilation) against a large range of in-situ and satellite-based observations of ozone, CO, VOC's and chlorine-containing trace gases for both troposphere and stratosphere. This analysis aims to provide a measure of model uncertainty in the operational system for tracers that are not, or poorly, constrained by data assimilation. It aims also to provide guidance on the directions for further model improvement with regard to the chemical conversion module.

  19. Establishment of an atmospheric observatory for trace gases and atmospheric oxygen in Namibia

    Science.gov (United States)

    Morgan, E.; Lavrič, J.; Seely, M.; Heimann, M.

    2012-04-01

    Continuous, high-precision measurements of greenhouse and other biogeochemically significant atmospheric gases help to establish a global baseline and create important data for the study of atmospheric transport, biogeochemical fluxes, and human emissions. Also, they can validate models and ground- and space-based remote sensing and complement airborne atmospheric measurements. There are currently few such facilities on the African continent. To reduce this gap in the global observational system, we are establishing an atmospheric observatory at Gobabeb, Namibia. Continuous measurements of the atmospheric O2/N2 ratio and biogeochemical trace gases (CO2, CH4, N2O, CO) will be accompanied by a regular flask sampling program. Our observatory also represents an opportunity to forge partnerships with local and global scientific organizations. The site is well located to study the natural and anthropogenic gas fluxes on the southern subtropical African continent, and the air-sea gas fluxes of the nearby Benguela Current system off the Namibian coast. This current system drives one of the four major eastern-boundary upwelling ecosystems, creating zones of intensive primary production that influence the budgets of atmospheric gases via air-sea exchange. Another feature of interest is the large biomass burning region in central and southern Africa. An analysis of HYSPLIT air mass back trajectories from Gobabeb indicate that the dominant origin of air at the site is from one of these two areas. On-site installation of the standalone measurement system, which is installed in a 20' container, is scheduled for the first half of 2012. We present here the detailed setup of the system and first performance data.

  20. MAX-DOAS aerosol and trace gases measurements in megacities in China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin [Institut fuer Energie- und Klimaforschung, Forschungszentrum Juelich (Germany); College of Environmental Science and Engineering Peking University, Beijing (China); Brauers, Theo [Institut fuer Energie- und Klimaforschung, Forschungszentrum Juelich (Germany); Shao, Min [College of Environmental Science and Engineering Peking University, Beijing (China)

    2011-07-01

    Multi Axis Differential Optical Absorption Spectroscopy (MAXDOAS) is a new remote sensing technique to measure atmospheric trace gases. Compared to other areas in the world, the atmospheric observations in megacities in China are rather limited. We present MAX-DOAS measurements at four sites in Beijing and Guangzhou in 2006 and 2008. At each site, the scattered sunlight was recorded at 7 elevation angles for about 1 months. Using the zenith spectrum as reference, the Differential Slant Column Densities (DSCDs) of HCHO, CHOCHO, O{sub 4} and NO{sub 2} at offaxis viewing geometries were derived from the DOAS fit. These DSCDs were simulated using a backward Monte Carlo radiative transfer model. The aerosol and trace gas profiles were defined by 3 parameters: the integrated quantities (T), the height of the surface layer (H), and the fraction of T below H. We fitted the modeled values to the measured values at the corresponding viewing geometries by varying the 3 parameters. The aerosol extinction and the boundary layer height were successfully retrieved from the measured O{sub 4} DSCDs as well as ground level concentrations of CHOCHO, HCHO, and NO{sub 2}, the latter being compared to simultaneous in-situ measurements.

  1. A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases.

    Science.gov (United States)

    Ohira, Shin-Ichi; Miki, Yusuke; Matsuzaki, Toru; Nakamura, Nao; Sato, Yu-ki; Hirose, Yasuo; Toda, Kei

    2015-07-30

    Industrial gases such as nitrogen, oxygen, argon, and helium are easily contaminated with water during production, transfer and use, because there is a high volume fraction of water in the atmosphere (approximately 1.2% estimated with the average annual atmospheric temperature and relative humidity). Even trace water (industrial gases can cause quality problems in the process such as production of semiconductors. Therefore, it is important to monitor and to control trace water levels in industrial gases at each supplying step, and especially during their use. In the present study, a fiber optic gas sensor was investigated for monitoring trace water levels in industrial gases. The sensor consists of a film containing a metal organic framework (MOF). MOFs are made of metals coordinated to organic ligands, and have mesoscale pores that adsorb gas molecules. When the MOF, copper benzene-1,3,5-tricarboxylate (Cu-BTC), was used as a sensing material, we investigated the color of Cu-BTC with water adsorption changed both in depth and tone. Cu-BTC crystals appeared deep blue in dry gases, and then changed to light blue in wet gases. An optical gas sensor with the Cu-BTC film was developed using a light emitting diode as the light source and a photodiode as the light intensity detector. The sensor showed a reversible response to trace water, did not require heating to remove the adsorbed water molecules. The sample gas flow rate did not affect the sensitivity. The obtained limit of detection was 40 parts per billion by volume (ppbv). The response time for sample gas containing 2.5 ppmvH2O was 23 s. The standard deviation obtained for daily analysis of 1.0 ppmvH2O standard gas over 20 days was 9%. Furthermore, the type of industrial gas did not affect the sensitivity. These properties mean the sensor will be applicable to trace water detection in various industrial gases. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Exomars orbiter science and data-relay mission / looking for trace gases on Mars

    Science.gov (United States)

    Fratacci, Olivier

    EXOMARS Orbiter Module: looking for trace gas on Mars and providing data relay support for future Mars Surface assets O.Fratacci, M.Mesrine, H.Renault, Thales Alenia Space France B.Musetti, M.Montagna, Thales Alenia Space Italy M.Kesselmann, M.Barczewski OHB P.Mitschdoerfer, D.Dellantonio Euro-pean Space Agency / ESTEC The European Space Agency (ESA) in a joint cooperation with NASA, will launch in 2016 the EXOMARS spacecraft composite to develop European landing technologies and provide a science orbiter with data-relay capability around Mars until end 2022. The spacecraft composite is composed of the Orbitr Module (OM), provided by TAS-France, an entry descent and landing demonstrator module (EDM) provided by TAS-Italy, and a set of six scientific payloads to be selected by the JPL during 2010. Recent observations of the planet Mars have indicated detection of methane as well as temporal, perhaps spatial variability in the detected signal while current photochemical models cannot explain the presence of methane in the atmosphere of Mars nor its reported rapid variations in space and time. The triple scientific objectives that drive the selection of these six instruments for the Exomars 2016 mission is to detect trace gases in Mars atmosphere, to characterise their spatial and temporal variation and to explore the source of the key trace gases (e.g. methane) on the surface. The launch is scheduled in January 2016 from Kennedy Space Center (KSC) using an ATLAS V 421 launcher with a total launch mass of 4.4 tons. After release of the EDM on Mars, the OM will perform the Mars Orbit Insertion manoeuvre and then reduce its elliptic orbit by implementing the first European Aerobraking around Mars for about 6 to 9 months, to finally end on a circular 400x400km orbit with an altitude in the range of 350km to 420km. From this orbit, a science phase will follow lasting 2 years in which the Mars atmosphere and surface is continuously observed. Science instruments composed of

  3. Carbon dioxide Information Analysis Center and World Data Center: A for Atmospheric trace gases. Annual progress report, FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Burtis, M.D. [comp.] [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.R.; Stoss, F.W. [Oak Ridge National Lab., TN (United States)

    1995-03-01

    This report summarizes the activities and accomplishments made by the Carbon Dioxide Information Analysis Center and World Data Center-A for Atmospheric Trace Gases during the fiscal year 1994. Topics discussed in this report include; organization and staff, user services, systems, communications, Collaborative efforts with China, networking, ocean data and activities of the World Data Center-A.

  4. Heavy metals and related trace elements

    International Nuclear Information System (INIS)

    Leland, H.V.; Luoma, S.N.; Wilkes, D.J.

    1977-01-01

    A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow trout

  5. Taking the atmosphere's pulse: The application of GC-IRMS to stable isotopes in atmospheric trace gases

    International Nuclear Information System (INIS)

    Lowe, D.C.; Ferretti, D.J.; Francey, R.J.; Allison, C.E.

    2001-01-01

    Since the industrial revolution, the abundance of many atmospheric trace gases has changed significantly. This is of concern because many of these trace species play a fundamental role in determining physical and chemical properties of the atmosphere important for maintaining life on earth. The impacts of the changes have been studied by a combination of analytical and theoretical modelling techniques. Stable isotope measurements made by conventional dual inlet IRMS for example, have provided valuable constraints on the budgets and removal mechanisms of key atmospheric trace gases. Unfortunately, in most cases, the application of these methods has been limited, because large air samples and cumbersome off line processing techniques are required to pre-concentrate enough gas for analysis. GC-IRMS offers a very attractive alternative because it combines on line processing with air sample size requirements typically 1000 times less than used in conventional techniques. In this article we focus on the requirements imposed on GC-IRMS by some of the current applications in atmospheric trace gas research. In addition, we examine some of the analytical and calibration aspects of the method applied to this kind of work. We finish with a summary of some of the comparative advantages and disadvantages of the GC-IRMS technique and some suggestions for future research using the method applied to specific atmospheric trace gases. (author)

  6. Characterization of atmospheric trace gases and particulate matter in Hangzhou, China

    Directory of Open Access Journals (Sweden)

    G. Zhang

    2018-02-01

    Full Text Available The Yangtze River Delta (YRD is one of the most densely populated regions in China with severe air quality issues that have not been fully understood. Thus, in this study, based on 1-year (2013 continuous measurement at a National Reference Climatological Station (NRCS, 30.22° N, 120.17° E; 41.7 m a.s.l. in the center of Hangzhou in the YRD, we investigated the seasonal characteristics, interspecies relationships, and the local emissions and the regional potential source contributions of trace gases (including O3, NOx, NOy, SO2, and CO and particulate matter (PM2.5 and PM10. Results revealed that severe two-tier air pollution (photochemical and haze pollution occurred in this region, with frequent exceedances in O3 (38 days and PM2.5 (62 days. O3 and PM2.5 both exhibited distinct seasonal variations with reversed patterns: O3 reaching a maximum in warm seasons (May and July but PM2.5 reaching a maximum in cold seasons (November to January. The overall results from interspecies correlation indicated a strong local photochemistry favoring the O3 production under a volatile organic compound (VOC-limited regime, whereas it moved towards an optimum O3 production zone during warm seasons, accompanied by the formation of secondary fine particulates under high O3. The emission maps of PM2.5, CO, NOx, and SO2 demonstrated that local emissions were significant for these species on a seasonal scale. The contributions from the regional transport among inland cities (Zhejiang, Jiangsu, Anhui, and Jiangxi Province on a seasonal scale were further confirmed to be crucial to air pollution at the NRCS site by using backward trajectory simulations. Air masses transported from the offshore areas of the Yellow Sea, East Sea, and South Sea were also found to be highly relevant to the elevated O3 at the NRCS site through the analysis of potential source contribution function (PSCF. Case studies of photochemical pollution (O3 and haze (PM2.5 episodes both

  7. Development of 2-D-MAX-DOAS and retrievals of trace gases and aerosols optical properties

    Science.gov (United States)

    Ortega, Ivan

    Air pollution is a major problem worldwide that adversely a_ects human health, impacts ecosystems and climate. In the atmosphere, there are hundreds of important compounds participating in complex atmospheric reactions linked to air quality and climate. Aerosols are relevant because they modify the radiation balance, a_ect clouds, and thus Earth albedo. The amount of aerosol is often characterized by the vertical integral through the entire height of the atmosphere of the logarithm fraction of incident light that is extinguished called Aerosol Optical Depth (AOD). The AOD at 550 nm (AOD550) over land is 0.19 (multi annual global mean), and that over oceans is 0.13. About 43 % of the Earth surface shows AOD550 smaller than 0.1. There is a need for measurement techniques that are optimized to measure aerosol optical properties under low AOD conditions, sample spatial scales that resemble satellite ground-pixels and atmospheric models, and help integrate remote sensing and in-situ observations to obtain optical closure on the effects of aerosols and trace gases in our changing environment. In this work, I present the recent development of the University of Colorado two dimensional (2-D) Multi-AXis Differential Optical Absorption Spectroscopy (2-D-MAX-DOAS) instrument to measure the azimuth and altitude distribution of trace gases and aerosol optical properties simultaneously with a single instrument. The instrument measures solar scattered light from any direction in the sky, including direct sun light in the hyperspectral domain. In Chapter 2, I describe the capabilities of 2-D measurements in the context of retrievals of azimuth distributions of nitrogen dioxide (NO2), formaldehyde (HCHO), and glyoxal (CHOCHO), which are precursors for tropospheric O3 and aerosols. The measurements were carried out during the Multi-Axis DOAS Comparison campaign for Aerosols and Trace gases (MAD-CAT) campaign in Mainz, Germany and show the ability to bridge spatial scales to

  8. Preparation and analysis of zero gases for the measurement of trace VOCs in air monitoring

    Science.gov (United States)

    Englert, Jennifer; Claude, Anja; Demichelis, Alessia; Persijn, Stefan; Baldan, Annarita; Li, Jianrong; Plass-Duelmer, Christian; Michl, Katja; Tensing, Erasmus; Wortman, Rina; Ghorafi, Yousra; Lecuna, Maricarmen; Sassi, Guido; Sassi, Maria Paola; Kubistin, Dagmar

    2018-06-01

    Air quality observations are performed globally to monitor the status of the atmosphere and its level of pollution and to assess mitigation strategies. Regulations of air quality monitoring programmes in various countries demand high-precision measurements for harmful substances often at low trace concentrations. These requirements can only be achieved by using high-quality calibration gases including high-purity zero gas. For volatile organic compound (VOC) observations, zero gas is defined as being hydrocarbon-free and can be, for example, purified air, nitrogen or helium. It is essential for the characterisation of the measurement devices and procedures, for instrument operation as well as for calibrations. Two commercial and one self-built gas purifiers were tested for their VOC removal efficiency following a standardised procedure. The tested gas purifiers included one adsorption cartridge with an inorganic media and two types of metal catalysts. A large range of VOCs were investigated, including the most abundant species typically measured at air monitoring stations. Both catalysts were able to remove a large range of VOCs whilst the tested adsorption cartridge was not suitable to remove light compounds up to C4. Memory effects occurred for the adsorption cartridge when exposed to higher concentration. This study emphasises the importance of explicitly examining a gas purifier for its intended application before applying it in the field.

  9. Emission rates of sulfur dioxide, trace gases and metals from Mount Erebus, Antartica

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, P.R.; Meeker, K. (New Mexico Institute of Mining and Technology, Socorro (USA)); Finnegan, D. (Los Alamos National Lab., NM (USA))

    1990-11-01

    SO{sub 2} emission rates have been measured annually since 1983 at Mount Erebus, Antarctica by correlation spectrometer (COSPEC V). Following a 4 month period of sustained strombolian activity in late 1984, SO{sub 2} emissions declined from 230 Mg/day in 1983 to 25 Mg/day and then slowly increased from 16 Mg/day in 1985 to 51 Mg/day in 1987. Nine sets of filter packs containing partcle and {sup 7}LiOH treated filters were collected in the plume in 1986 and analyzed by neutron activation. Using the COSPEC data and measured element/S ratios on the filters, emission rates have been determined for trace gases and metals. The authors infer HCl and HF emissions in 1983 to be about 1200 and 500 Mg/day, respectively. Mt Erebus has therefore been an important source of halogens to the Anarctic atmosphere and could be responsible for excess Cl found in Central Antarctica snow.

  10. Variations of trace gases over the Bay of Bengal during the summer monsoon

    Science.gov (United States)

    Girach, I. A.; Ojha, Narendra; Nair, Prabha R.; Tiwari, Yogesh K.; Kumar, K. Ravi

    2018-02-01

    In situ measurements of near-surface ozone (O3), carbon monoxide (CO), and methane (CH4) were carried out over the Bay of Bengal (BoB) as a part of the Continental Tropical Convergence Zone (CTCZ) campaign during the summer monsoon season of 2009. O3, CO and CH4 mixing ratios varied in the ranges of 8-54 ppbv, 50-200 ppbv and 1.57-2.15 ppmv, respectively during 16 July-17 August 2009. The spatial distribution of mean tropospheric O3 from satellite retrievals is found to be similar to that in surface O3 observations, with higher levels over coastal and northern BoB as compared to central BoB. The comparison of in situ measurements with the Monitoring Atmospheric Composition & Climate (MACC) global reanalysis shows that MACC simulations reproduce the observations with small mean biases of 1.6 ppbv, -2.6 ppbv and 0.07 ppmv for O3, CO and CH4, respectively. The analysis of diurnal variation of O3 based on observations and the simulations from Weather Research and Forecasting coupled with Chemistry (WRF-Chem) at a stationary point over the BoB did not show a net photochemical build up during daytime. Satellite retrievals show limitations in capturing CH4 variations as measured by in situ sample analysis highlighting the need of more shipborne in situ measurements of trace gases over this region during monsoon.

  11. Opo lidar sounding of trace atmospheric gases in the 3 – 4 μm spectral range

    Directory of Open Access Journals (Sweden)

    Romanovskii Oleg A.

    2018-01-01

    Full Text Available The applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO generation to lidar sounding of the atmosphere in the spectral range 3–4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases (TAG is based on differential absorption lidar (DIAL method and differential optical absorption spectroscopy (DOAS. The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases. The numerical simulation performed shows that a KTA-based OPO laser is a promising source of radiation for remote DIAL-DOAS sounding of the TAGs under study along surface tropospheric paths. A possibility of using a PD38-03-PR photodiode for the DIAL gas analysis of the atmosphere is shown.

  12. OH reactivity and potential SOA yields from volatile organic compounds and other trace gases measured in controlled laboratory biomass burns

    Science.gov (United States)

    J. B. Gilman; C. Warneke; W. C. Kuster; P. D. Goldan; P. R. Veres; J. M. Roberts; J. A. de Gouw; I. R. Burling; R. J. Yokelson

    2010-01-01

    A comprehensive suite of instruments were used to characterize volatile organic compounds (VOCs) and other trace gases (e.g., CO, CH4, NO2, etc.) emitted from controlled burns of various fuel types common to the Southeastern and Southwestern United States. These laboratory-based measurements were conducted in February 2009 at the U.S. Department of Agriculture’s Fire...

  13. Seasonal and spatial changes in trace gases over megacities from Aura TES observations: two case studies

    Directory of Open Access Journals (Sweden)

    K. E. Cady-Pereira

    2017-08-01

    Full Text Available The Aura Tropospheric Emission Spectrometer (TES is collecting closely spaced observations over 19 megacities. The objective is to obtain measurements that will lead to better understanding of the processes affecting air quality in and around these cities, and to better estimates of the seasonal and interannual variability. We explore the TES measurements of ozone, ammonia, methanol and formic acid collected around the Mexico City metropolitan area (MCMA and in the vicinity of Lagos (Nigeria. The TES data exhibit seasonal signals that are correlated with Atmospheric Infrared Sounder (AIRS CO and Moderate Resolution Imaging Spectroradiometer (MODIS aerosol optical depth (AOD, with in situ measurements in the MCMA and with Goddard Earth Observing System (GEOS-Chem model output in the Lagos area. TES was able to detect an extreme pollution event in the MCMA on 9 April 2013, which is also evident in the in situ data. TES data also show that biomass burning has a greater impact south of the city than in the caldera where Mexico City is located. TES measured enhanced values of the four species over the Gulf of Guinea south of Lagos. Since it observes many cities from the same platform with the same instrument and applies the same retrieval algorithms, TES data provide a very useful tool for easily comparing air quality measures of two or more cities. We compare the data from the MCMA and Lagos, and show that, while the MCMA has occasional extreme pollution events, Lagos consistently has higher levels of these trace gases.

  14. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2000 Annual Report; ANNUAL

    International Nuclear Information System (INIS)

    Cushman, R.M.

    2001-01-01

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO(sub 2)) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO(sub 2) and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO(sub 2) on vegetation; and the vulnerability of coastal areas to rising sea levels

  15. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2000 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2001-11-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  16. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2001 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2002-10-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on climate and vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Director) of DOE's Office of Biological and Environmental Research. CDIAC represents DOE in the multi-agency Global Change Data and Information System (GCDIS). Wanda Ferrell is DOE's Program Manager with overall responsibility for CDIAC. Roger Dahlman is responsible for CDIAC's AmeriFlux tasks, and Anna Palmisano for CDIAC's Ocean Data tasks. CDIAC is made

  17. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 1999 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2000-03-31

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global-change data and information analysis center of the Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has--since its inception in 1982--enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea level. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Acting Director) of DOE's Office of Biological and Environmental Research. CDIAC's FY 1999 budget was 2.2M dollars. CDIAC represents the DOE in the multi-agency Global Change Data and Information System. Bobbi Parra, and Wanda Ferrell on an interim basis, is DOE's Program Manager with responsibility for CDIAC. CDIAC comprises three groups, Global Change Data, Computer Systems, and

  18. The airborne mass spectrometer AIMS – Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

    Directory of Open Access Journals (Sweden)

    T. Jurkat

    2016-04-01

    an isotopically labeled 34SO2 standard. In addition, we report on trace gas measurements of HONO, which is sensitive to the reaction with SF5−. The detection limit for the various trace gases is in the low 10 pptv range at a 1 s time resolution with an overall uncertainty of the measurement of the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO (High Altitude LOng range research aircraft. As an example, measurements conducted during the TACTS/ESMVal (Transport and Composition of the LMS/UT and Earth System Model Validation mission with HALO in 2012 are presented, focusing on a classification of tropospheric and stratospheric influences in the UTLS region. The combination of AIMS measurements with other measurement techniques yields a comprehensive picture of the sulfur, chlorine and reactive nitrogen oxide budget in the UTLS. The different trace gases measured with AIMS exhibit the potential to gain a better understanding of the trace gas origin and variability at and near the tropopause.

  19. Energy–pressure relation for low-dimensional gases

    Directory of Open Access Journals (Sweden)

    Francesco Mancarella

    2014-10-01

    Full Text Available A particularly simple relation of proportionality between internal energy and pressure holds for scale-invariant thermodynamic systems (with Hamiltonians homogeneous functions of the coordinates, including classical and quantum – Bose and Fermi – ideal gases. One can quantify the deviation from such a relation by introducing the internal energy shift as the difference between the internal energy of the system and the corresponding value for scale-invariant (including ideal gases. After discussing some general thermodynamic properties associated with the scale-invariance, we provide criteria for which the internal energy shift density of an imperfect (classical or quantum gas is a bounded function of temperature. We then study the internal energy shift and deviations from the energy–pressure proportionality in low-dimensional models of gases interpolating between the ideal Bose and the ideal Fermi gases, focusing on the Lieb–Liniger model in 1d and on the anyonic gas in 2d. In 1d the internal energy shift is determined from the thermodynamic Bethe ansatz integral equations and an explicit relation for it is given at high temperature. Our results show that the internal energy shift is positive, it vanishes in the two limits of zero and infinite coupling (respectively the ideal Bose and the Tonks–Girardeau gas and it has a maximum at a finite, temperature-depending, value of the coupling. Remarkably, at fixed coupling the energy shift density saturates to a finite value for infinite temperature. In 2d we consider systems of Abelian anyons and non-Abelian Chern–Simons particles: as it can be seen also directly from a study of the virial coefficients, in the usually considered hard-core limit the internal energy shift vanishes and the energy is just proportional to the pressure, with the proportionality constant being simply the area of the system. Soft-core boundary conditions at coincident points for the two-body wavefunction introduce

  20. Energy–pressure relation for low-dimensional gases

    International Nuclear Information System (INIS)

    Mancarella, Francesco; Mussardo, Giuseppe; Trombettoni, Andrea

    2014-01-01

    A particularly simple relation of proportionality between internal energy and pressure holds for scale-invariant thermodynamic systems (with Hamiltonians homogeneous functions of the coordinates), including classical and quantum – Bose and Fermi – ideal gases. One can quantify the deviation from such a relation by introducing the internal energy shift as the difference between the internal energy of the system and the corresponding value for scale-invariant (including ideal) gases. After discussing some general thermodynamic properties associated with the scale-invariance, we provide criteria for which the internal energy shift density of an imperfect (classical or quantum) gas is a bounded function of temperature. We then study the internal energy shift and deviations from the energy–pressure proportionality in low-dimensional models of gases interpolating between the ideal Bose and the ideal Fermi gases, focusing on the Lieb–Liniger model in 1d and on the anyonic gas in 2d. In 1d the internal energy shift is determined from the thermodynamic Bethe ansatz integral equations and an explicit relation for it is given at high temperature. Our results show that the internal energy shift is positive, it vanishes in the two limits of zero and infinite coupling (respectively the ideal Bose and the Tonks–Girardeau gas) and it has a maximum at a finite, temperature-depending, value of the coupling. Remarkably, at fixed coupling the energy shift density saturates to a finite value for infinite temperature. In 2d we consider systems of Abelian anyons and non-Abelian Chern–Simons particles: as it can be seen also directly from a study of the virial coefficients, in the usually considered hard-core limit the internal energy shift vanishes and the energy is just proportional to the pressure, with the proportionality constant being simply the area of the system. Soft-core boundary conditions at coincident points for the two-body wavefunction introduce a length scale

  1. Distribution of trace gases and aerosols in the Siberian air shed during wildfires of summer 2012

    Science.gov (United States)

    Belan, Boris D.; Paris, Jean-Daiel; Nedelec, Philippe; Antokhin, Pavel N.; Arshinova, Victoriya; Arshinov, Mikhail Yu.; Belan, Sergey B.; Davydov, Denis K.; Ivlev, Georgii A.; Fofonov, Alexandre V.; Kozlov, Artem V.; Rasskazchikova, Tatyana M.; Savkin, Denis E.; Simonenkov, Denis V.; Sklyadneva, Tatyana K.; Tolmachev, Gennadii N.

    2017-04-01

    During the last two decades, three strong biomass burning events have been observed in Russia: two of them in 2002 and 2010 in the European part of Russia, and another one in 2012 in West and East Siberia. In this paper we present results of the extensive airborne study of the vertical distribution of trace gases and aerosols carried out during strong wildfire event happened in summer 2012 in Siberia. For this purpose, the Optik TU-134 aircraft laboratory was used as a research platform. A large-scale airborne campaign has been undertaken along the route Novosibirsk-Mirny-Yakutsk-Bratsk-Novosibirsk on 31st of July and 1st of August, 2012. Flight pattern consisted of a number of ascents and descents between close to the ground and 8 km altitude that enabled 20 vertical profiles to be obtained. Campaign was conducted under the weather conditions of low-gradient baric field that determined the low speed transport of air masses, as well as the accumulation of biomass burning emissions in the region under study. Highest concentrations of CO2, CH4 and CO over wildfire spots reached 432 ppm, 2367 ppb, and 4036 ppb, correspondingly. If we exclude from the analysis the data obtained when crossing smoke plumes, we can find a difference between background concentrations measured in the atmosphere over regions affected by biomass burning and clean areas. Enhancement of CO2 over the wildfire areas changed with altitude. On average, it was 10.5 ppm in the atmospheric boundary layer (ABL) and 5-6 ppm in the free troposphere. Maximum CO2 enhancements reached 27 ppm and 24 ppm, correspondingly. The averaged CH4 enhancement varied from 75 ppb in the boundary layer to 30 ppb in the upper troposphere, and a little bit lower than 30 ppb in the middle troposphere. Maximum CH4 enhancements reached 202 ppb, 108 ppb, and 50-60 ppb, correspondingly. The averaged and maximum enhancements of CO differed by an order of magnitude. Thus, in the ABL the maximum difference in concentration between

  2. Characteristics of aerosol particles and trace gases in ship exhaust plumes

    Science.gov (United States)

    Drewnick, F.; Diesch, J.; Borrmann, S.

    2011-12-01

    Gaseous and particulate matter from marine vessels gain increasing attention due to their significant contribution to the anthropogenic burden of the atmosphere, implying the change of the atmospheric composition and the impact on local and regional air quality and climate (Eyring et al., 2010). As ship emissions significantly affect air quality of onshore regions, this study deals with various aspects of gas and particulate plumes from marine traffic measured near the Elbe river mouth in northern Germany. In addition to a detailed investigation of the chemical and physical particle properties from different types of commercial marine vessels, we will focus on the chemistry of ship plumes and their changes while undergoing atmospheric processing. Measurements of the ambient aerosol, various trace gases and meteorological parameters using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe which is passed on average, daily by 30 ocean-going vessels reaching the port of Hamburg, the second largest freight port of Europe. During 5 days of sampling from April 25-30, 2011 170 commercial marine vessels were probed at a distance of about 1.5-2 km with high temporal resolution. Mass concentrations in PM1, PM2.5 and PM10 and number as well as PAH and black carbon (BC) concentrations in PM1 were measured; size distribution instruments covered the size range from 6 nm up to 32 μm. The chemical composition of the non-refractory aerosol in the submicron range was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gas concentrations in the air and a weather station provided meteorological parameters. Additionally, a wide spectrum of ship information for each vessel including speed, size, vessel type, fuel type, gross tonnage and engine power was recorded via Automatic Identification System (AIS) broadcasts. Although commercial marine vessels powered by diesel engines consume high

  3. Freeze dried samples of volcanic gases - a new method for the determination of trace elements by NAA

    International Nuclear Information System (INIS)

    Bichler, M.; Sortino, F.

    1997-01-01

    A new routine technique for the determination of trace elements in volcanic gases by NAA is presented. For time and money saving reasons this method is applicable to samples, collected by the conventional method. This technique uses evacuated glass bottles, partly filled with NaOH solution to absorb acidic gas components and CO 2 , which is the main constituent of the incondensable gas fraction at ambient conditions. The application of NAA to samples collected by this method shows two main sources of difficulties: drying of NaOH without loosing volatile elements of interest (in particular Hg and Se) and the high activities of 24 Na after neutron irradiation. The first can be avoided by liquid irradiation, thereby limiting the irradiation time, the second excludes the determination of short and medium lived nuclides because of the high γ-background due to 24 Na. A new freeze drying technique enables the application of long irradiation times and therefore the use of long-lived activation products for analysis. The samples of volcanic gases were collected at the fumarole fields of La Fossa volcano on the island Vulcano. Southern Italy. This technique allows very sensitive determinations of trace elements in volcanic gases and adds highly valuable information to the understanding and modeling of volcanic gas sources. (orig.)

  4. Technical Note: A new global database of trace gases and aerosols from multiple sources of high vertical resolution measurements

    Directory of Open Access Journals (Sweden)

    G. E. Bodeker

    2008-09-01

    Full Text Available A new database of trace gases and aerosols with global coverage, derived from high vertical resolution profile measurements, has been assembled as a collection of binary data files; hereafter referred to as the "Binary DataBase of Profiles" (BDBP. Version 1.0 of the BDBP, described here, includes measurements from different satellite- (HALOE, POAM II and III, SAGE I and II and ground-based measurement systems (ozonesondes. In addition to the primary product of ozone, secondary measurements of other trace gases, aerosol extinction, and temperature are included. All data are subjected to very strict quality control and for every measurement a percentage error on the measurement is included. To facilitate analyses, each measurement is added to 3 different instances (3 different grids of the database where measurements are indexed by: (1 geographic latitude, longitude, altitude (in 1 km steps and time, (2 geographic latitude, longitude, pressure (at levels ~1 km apart and time, (3 equivalent latitude, potential temperature (8 levels from 300 K to 650 K and time.

    In contrast to existing zonal mean databases, by including a wider range of measurement sources (both satellite and ozonesondes, the BDBP is sufficiently dense to permit calculation of changes in ozone by latitude, longitude and altitude. In addition, by including other trace gases such as water vapour, this database can be used for comprehensive radiative transfer calculations. By providing the original measurements rather than derived monthly means, the BDBP is applicable to a wider range of applications than databases containing only monthly mean data. Monthly mean zonal mean ozone concentrations calculated from the BDBP are compared with the database of Randel and Wu, which has been used in many earlier analyses. As opposed to that database which is generated from regression model fits, the BDBP uses the original (quality controlled measurements with no smoothing applied in any

  5. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.

    Science.gov (United States)

    Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J

    2016-01-01

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.

  6. Reducing the Livestock related green house gases emission

    Directory of Open Access Journals (Sweden)

    D Indira

    2012-08-01

    Full Text Available Cattle rearing generate more global warming green house gases than driving cars. These green house gases leads to changes in the climate. This climate change affects the livestock, man and natural environment continuously. For this reason it is important for livestock farmers to find the ways which minimize these gases emission. In this article the causes of climate change and effects, measures to be taken by farmers and their efficiency in reducing green house gases emission were reviewed briefly to make the farmers and students aware of the reduction of global warming green house gases and measures to be taken for reducing these gases. [Vet. World 2012; 5(4.000: 244-247

  7. Analysis of trace gases at ppb levels by proton transfer reaction mass spectrometry (PTR-MS)

    International Nuclear Information System (INIS)

    Lindinger, W.; Hansel, A.

    1996-01-01

    A proton transfer reaction mass spectrometry (PTR-MS) system has been developed which allows for on-line measurements of trace gas components with concentrations as low as 1 ppb. The method is based on reactions of H 3 O + ions, which perform non-dissociative proton transfer to most of the common organic trace constituents but do not react with any of the components present in clean air. Examples of medical information obtained by means of breath analysis, of environmental trace analysis, and examples in the field of food chemistry demonstrate the wide applicability of the method. (Authors)

  8. A Nanoparticulate Photocatalytic Filter for Removal of Trace Contaminant Gases, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Maintaining a healthy atmosphere in closed life support systems is necessary for the well being of the crew and success of a space mission. Current trace contaminant...

  9. Source apportionment of particulate matter and trace gases near a major refinery near the Houston Ship Channel

    Science.gov (United States)

    Wallace, Henry W.; Sanchez, Nancy P.; Flynn, James H.; Erickson, Mathew H.; Lefer, Barry L.; Griffin, Robert J.

    2018-01-01

    From February 7 to 27, 2015, a mobile air quality laboratory was deployed to a location proximate to a major refinery, the Port of Houston, and several neighborhoods to conduct measurements of atmospheric trace gases and particulate matter. Two statistical models were utilized to apportion the sources of pollution impacting this site and the denizens of the nearby neighborhoods. Positive matrix factorization (PMF) was performed on the organic signal of the aerosol mass spectra, resulting in five factors totaling an average of 4.1 μg/m3 of the organic aerosol: hydrocarbon-like (0.67 μg/m3), cooking (0.35 μg/m3) biomass burning (1.14 μg/m3), low-volatility oxidized (1.15 μg/m3), and semi-volatile oxidized (0.78 μg/m3). Principal component analysis was performed on daytime and nighttime data, including concentrations from PMF output, of other PM1 components, and of trace gases. This generated five daytime and five nighttime factors that explained 74.5% and 73.0% of the variance, respectively. The most important factors impacting this site were from mobile source exhaust and petrochemical aromatic compound emissions. Together these two factors also constitute most of the observed carcinogens.

  10. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases, Fiscal Year 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2003-08-28

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including atmospheric concentrations and atmospheric emissions of carbon dioxide (CO{sub 2}) and other radiatively active gases; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  11. CARBON TRACE GASES IN LAKE AND BEAVER POND ICE NEAR THOMPSON, MANITOBA, CANADA

    Science.gov (United States)

    Concentrations of CO2, CO, and CH4 were measured in beaver pond and lake ice in April 1996 near Thompson, Manitoba to derive information on possible impacts of ice melting on corresponding atmospheric trace gas concentrations. CH4 concentrations in beaver pond and lake ice ranged...

  12. The benefit of limb cloud imaging for infrared limb sounding of tropospheric trace gases

    OpenAIRE

    G. Heinemann; P. Preusse; R. Spang; S. Adams

    2009-01-01

    Advances in detector technology enable a new generation of infrared limb sounders to measure 2-D images of the atmosphere. A proposed limb cloud imager (LCI) mode will detect clouds with a spatial resolution unprecedented for limb sounding. For the inference of temperature and trace gas distributions, detector pixels of the LCI have to be combined into super-pixels which provide the required signal-to-noise and information content for the retrievals. This study examines the extent to which tr...

  13. Airborne Measurements and Emission Estimates of Greenhouse Gases and Other Trace Constituents From the 2013 California Yosemite Rim Wildfire

    Science.gov (United States)

    Yates, E. L.; Iraci, L. T.; Singh, H. B.; Tanaka, T.; Roby, M. C.; Hamill, P.; Clements, C. B.; Lareau, N.; Contezac, J.; Blake, D. R.; hide

    2015-01-01

    This paper presents airborne measurements of multiple atmospheric trace constituents including greenhouse gases (such as CO2, CH4, O3) and biomass burning tracers (such as CO, CH3CN) downwind of an exceptionally large wildfire. In summer 2013, the Rim wildfire, ignited just west of the Yosemite National Park, California, and burned over 250,000 acres of the forest during the 2-month period (17 August to 24 October) before it was extinguished. The Rim wildfire plume was intercepted by flights carried out by the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX) on 29 August and the NASA DC-8, as part of SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys), on 26 and 27 August during its intense, primary burning period. AJAX revisited the wildfire on 10 September when the conditions were increasingly smoldering, with slower growth. The more extensive payload of the DC-8 helped to bridge key measurements that were not available as part of AJAX (e. g. CO). Data analyses are presented in terms of emission ratios (ER), emission factors (EF) and combustion efficiency and are compared with previous wildfire studies. ERs were 8.0 ppb CH4/(ppm CO2) on 26 August, 6.5 ppb CH4 (ppm CO2)1 on 29 August and 18.3 ppb CH4 (ppm CO2)1 on 10 September 2013. The increase in CH4 ER from 6.5 to 8.0 ppb CH4/(ppm CO2) during the primary burning period to 18.3 ppb CH4/(ppm CO2) during the fire's slower growth period likely indicates enhanced CH4 emissions from increased smoldering combustion relative to flaming combustion. Given the magnitude of the Rim wildfire, the impacts it had on regional air quality and the limited sampling of wildfire emissions in the western United States to date, this study provides a valuable dataset to support forestry and regional air quality management, including observations of ERs of a wide number of species from the Rim wildfire.

  14. Trace elements in relation to cardiovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Masironi, R [World Health Organization, Cardiovascular Diseases Unit, Geneva (Switzerland); Parr, R M [International Atomic Energy Agency, Medical Applications Section, Vienna (Austria)

    1973-07-01

    For the past four years the World Health Organization and the International Atomic Energy-Agency have been jointly coordinating investigations at an international level on the role possibly played by stable trace elements in the aetiology of cardiovascular diseases, and the use of nuclear techniques in studying these elements. (author)

  15. A portable infrared laser spectrometer for flux measurements of trace gases at the geosphere–atmosphere interface

    International Nuclear Information System (INIS)

    Guimbaud, C; Catoire, V; Robert, C; Chartier, M; Pomathiod, L; Gogo, S; Laggoun-Défarge, F; Albéric, P; Grossel, A; Nicoullaud, B; Richard, G

    2011-01-01

    A portable infrared laser absorption spectrometer named SPIRIT (SPectromètre Infra-Rouge In situ Troposphérique) has been set up for the simultaneous flux measurements of trace gases at the geosphere–atmosphere interface. It uses a continuous wave distributed feedback room temperature quantum cascade laser and a patented new optical multi-pass cell. The aim of SPIRIT field studies is to get a better understanding of land and water bodies to atmosphere exchange mechanisms of greenhouse gases (GHG). The analytical procedures to derive concentrations and fluxes are described, as well as the performances of the instrument under field conditions. The ability of SPIRIT to assess space and time dependence emissions of two GHG—nitrous oxide (N 2 O) and methane (CH 4 )—for different types of ecosystems is demonstrated through in situ measurements on peatland, on fertilized soil, and on water body systems. The objectives of these investigations and preliminary significant results are reported

  16. Impact of Convection and Long Range Transport on Short-Lived Trace Gases in the UT/LS

    Science.gov (United States)

    Atlas, E. L.; Schauffler, S.; Navarro, M. A.; Lueb, R.; Hendershot, R.; Ueyama, R.

    2017-12-01

    Chemical composition of the air in the upper troposphere/lower stratosphere is controlled by a balance of transport, photochemistry, and physical processes, such as interactions with clouds, ice, and aerosol. The chemistry of the air masses that reach the upper troposphere can potentially have profound impacts on the chemistry in the near tropopause region. For example, the transport of reactive organic halogens and their transformation to inorganic halogen species, e.g., Br, BrO, etc., can have a significant impact on ozone budgets in this region and even deeper the stratosphere. Trace gas measurements in the region near the tropopause can also indicate potential sources of surface emissions that are transported to high altitudes. Measurement of trace gases, including such compounds as non-methane hydrocarbons, hydrochlorofluorocarbons, halogenated solvents, methyl halides, etc., can be used to characterize source emissions from industrial, urban, biomass burning, or marine origins. Recent airborne research campaigns have been conducted to better characterize the chemical composition and variations in the UT/LS region. This presentation will discuss these measurements, with a special emphasis on the role of convection and transport in modifying the chemical composition of the UT/LS.

  17. Flow immune photoacoustic sensor for real-time and fast sampling of trace gases

    Science.gov (United States)

    Petersen, Jan C.; Balslev-Harder, David; Pelevic, Nikola; Brusch, Anders; Persijn, Stefan; Lassen, Mikael

    2018-02-01

    A photoacoustic (PA) sensor for fast and real-time gas sensing is demonstrated. The PA cell has been designed for flow noise immunity using computational fluid dynamics (CFD) analysis. PA measurements were conducted at different flow rates by exciting molecular C-H stretch vibrational bands of hexane (C6H14) in clean air at 2950cm-1 (3.38 μm) with a custom made mid-infrared interband cascade laser (ICL). The PA sensor will contribute to solve a major problem in a number of industries using compressed air by the detection of oil contaminants in high purity compressed air. We observe a (1σ, standard deviation) sensitivity of 0.4 +/-0.1 ppb (nmol/mol) for hexane in clean air at flow rates up to 2 L/min, corresponding to a normalized noise equivalent absorption (NNEA) coefficient of 2.5×10-9 W cm-1 Hz1/2, thus demonstrating high sensitivity and fast and real-time gas analysis. The PA sensor is not limited to molecules with C-H stretching modes, but can be tailored to measure any trace gas by simply changing the excitation wavelength (i.e. the laser source) making it useful for many different applications where fast and sensitive trace gas measurements are needed.

  18. Measurement of gas/water uptake coefficients for trace gases active in the marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Davidovits, P. (Boston Coll., Chestnut Hill, MA (United States). Dept. of Chemistry); Worsnop, D.W.; Zahniser, M.S.; Kolb, C.E. (Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics)

    1992-02-01

    Ocean produced reduced sulfur compounds including dimethylsulfide (DMS), hydrogen sulfide (H{sub 2}S), carbon disulfide (CS{sub 2}), methyl mercaptan (CH{sub 3}CH) and carbonyl sulfide (OCS) deliver a sulfur burden to the atmosphere which is roughly equal to sulfur oxides produced by fossil fuel combustion. These species and their oxidation products dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO{sub 2}) and methane sulfonic acid (MSA) dominate aerosol and CCN production in clean marine air. Furthermore, oxidation of reduced sulfur species will be strongly influenced by NO{sub x}/O{sub 3} chemistry in marine atmospheres. The multiphase chemical processes for these species must be understood in order to study the evolving role of combustion produced sulfur oxides over the oceans. We have measured the chemical and physical parameters affecting the uptake of reduced sulfur compounds, their oxidation products, ozone, and nitrogen oxides by the ocean's surface, and marine clouds, fogs, and aerosols. These parameters include: gas/surface mass accommodation coefficients; physical and chemically modified (effective) Henry's law constants; and surface and liquid phase reaction constants. These parameters are critical to understanding both the interaction of gaseous trace species with cloud and fog droplets and the deposition of trace gaseous species to dew covered, fresh water and marine surfaces.

  19. Trapping, chemistry, and export of trace gases in the South Asian summer monsoon observed during CARIBIC flights in 2008

    Directory of Open Access Journals (Sweden)

    A. Rauthe-Schöch

    2016-03-01

    Full Text Available The CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container passenger aircraft observatory performed in situ measurements at 10–12 km altitude in the South Asian summer monsoon anticyclone between June and September 2008. These measurements enable us to investigate this atmospheric region (which so far has mostly been observed from satellites using the broad suite of trace gases and aerosol particles measured by CARIBIC. Elevated levels of a variety of atmospheric pollutants (e.g. carbon monoxide, total reactive nitrogen oxides, aerosol particles, and several volatile organic compounds were recorded. The measurements provide detailed information about the chemical composition of air in different parts of the monsoon anticyclone, particularly of ozone precursors. While covering a range of 3500 km inside the monsoon anticyclone, CARIBIC observations show remarkable consistency, i.e. with distinct latitudinal patterns of trace gases during the entire monsoon period. Using the CARIBIC trace gas and aerosol particle measurements in combination with the Lagrangian particle dispersion model FLEXPART, we investigated the characteristics of monsoon outflow and the chemical evolution of air masses during transport. The trajectory calculations indicate that these air masses originated mainly from South Asia and mainland Southeast Asia. Estimated photochemical ages of the air were found to agree well with transport times from a source region east of 90–95° E. The photochemical ages of the air in the southern part of the monsoon anticyclone were systematically younger (less than 7 days and the air masses were mostly in an ozone-forming chemical mode. In its northern part the air masses were older (up to 13 days and had unclear ozone formation or destruction potential. Based on analysis of forward trajectories, several receptor regions were identified. In addition to predominantly westward

  20. Time resolved investigations on biogenic trace gases exchanges using proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Karl, T.

    2000-02-01

    1999/2000 completed this thesis and were used to evaluate and confirm the previously described investigations. The outcome of these measurements are summarized in the following abstracts submitted to the EGS 2000 (Nizza, France) and SASP 2000 (Folgaria, Italy) conferences: 1. Volatile organic compounds (VOCs) in the free troposphere at the Sonnblick Observatory, Austria (3106 m a.s.l.) were measured during November 1999. VOCs in the 0.5 to 5 ppbv range included hexenals, hexanal, methylbutanals, and especially 1-penten-3-ol; even higher levels of acetaldehyde (5 to 26 ppbv) were measured. The common origins of these compounds are proposed to be leaves which are senescing and/or subjected to freeze-thaw damage; this is inferred from laboratory investigations and by tracing air mass trajectories to urban or rural sites. This work suggests the Earth's deciduous forests may release large amounts of reactive VOCs during the autumn. 2. A PTR-MS-GC system was set up to identify lipoxygenase peroxidation products during freezing induced wounding, senescing and general wounding in various plants. In all laboratory experiments we observed substantial production of 1-penten-3-ol, cis-2-penten-1-ol, hexenal and hexenol isomers, all reactive oxygenates that contribute to tropospheric chemistry. Special attention is drawn to the production of pentenols, compounds which have not been reported to be present in large amounts in the atmosphere. PTR-MS online measurements on the Sonnblick observatory in the Austrian Alps (3106 m) show that even in the free troposphere substantial amounts of pentenols can be present as the result of ongoing freezing and senescing in deciduous plants. We also observed high mixing ratios of hexenals, acetaldehyde, methanol, 2-methylbutanal, 3-methylbutanal, EVK and acetone, all coming from local vegetation near the Sonnblick. 3. It was possible to estimate OH-radical concentrations on the 27 th November 1999 at the Sonnblick Observatory. During daytime the

  1. Laser Fluence Recognition Using Computationally Intelligent Pulsed Photoacoustics Within the Trace Gases Analysis

    Science.gov (United States)

    Lukić, M.; Ćojbašić, Ž.; Rabasović, M. D.; Markushev, D. D.; Todorović, D. M.

    2017-11-01

    In this paper, the possibilities of computational intelligence applications for trace gas monitoring are discussed. For this, pulsed infrared photoacoustics is used to investigate SF6-Ar mixtures in a multiphoton regime, assisted by artificial neural networks. Feedforward multilayer perceptron networks are applied in order to recognize both the spatial characteristics of the laser beam and the values of laser fluence Φ from the given photoacoustic signal and prevent changes. Neural networks are trained in an offline batch training regime to simultaneously estimate four parameters from theoretical or experimental photoacoustic signals: the laser beam spatial profile R(r), vibrational-to-translational relaxation time τ _{V-T} , distance from the laser beam to the absorption molecules in the photoacoustic cell r* and laser fluence Φ . The results presented in this paper show that neural networks can estimate an unknown laser beam spatial profile and the parameters of photoacoustic signals in real time and with high precision. Real-time operation, high accuracy and the possibility of application for higher intensities of radiation for a wide range of laser fluencies are factors that classify the computational intelligence approach as efficient and powerful for the in situ measurement of atmospheric pollutants.

  2. The use of stable isotopes to trace the impact of landfill gases on environmental waters

    International Nuclear Information System (INIS)

    Kennel, P.; Hendy, C.H.

    1997-01-01

    The process of anaerobic fermentation leading to methanogenisis in landfills produces isotopically depleted methane and isotopically enriched carbon dioxide. While the inflammability of methane is a recognised environmental hazard, the impact of the carbon dioxide produced has not been recognised. Unlike methane, the carbon dioxide is very soluble in waters it comes in contact with and unlike leachates it is not contained by the engineered structure of modern landfills. The carbon dioxide gas has the potential of dissolving in ground waters, lowering their pH and degrading their water quality. We have used up to +13 per thousand delta/sup 13/C values of the CO/sub 2/ gas to trace and quantify the effect of the enhanced P/sub CO2/ on groundwater. The downstream consequences of enhanced P/sub CO2/ on groundwater quality also depend on matrix lithology, being more significant for basaltic environments such as those typical of Auckland landfills than for the rhyolitic sands and gravels common in Waikato landfills. (author)

  3. The benefit of limb cloud imaging for infrared limb sounding of tropospheric trace gases

    Directory of Open Access Journals (Sweden)

    G. Heinemann

    2009-06-01

    Full Text Available Advances in detector technology enable a new generation of infrared limb sounders to measure 2-D images of the atmosphere. A proposed limb cloud imager (LCI mode will detect clouds with a spatial resolution unprecedented for limb sounding. For the inference of temperature and trace gas distributions, detector pixels of the LCI have to be combined into super-pixels which provide the required signal-to-noise and information content for the retrievals. This study examines the extent to which tropospheric coverage can be improved in comparison to limb sounding using a fixed field of view with the size of the super-pixels, as in conventional limb sounders. The study is based on cloud topographies derived from (a IR brightness temperatures (BT of geostationary weather satellites in conjunction with ECMWF temperature profiles and (b ice and liquid water content data of the Consortium for Small-scale Modeling-Europe (COSMO-EU of the German Weather Service. Limb cloud images are simulated by matching the cloud topography with the limb sounding line of sight (LOS. The analysis of the BT data shows that the reduction of the spatial sampling along the track has hardly any effect on the gain in information. The comparison between BT and COSMO-EU data identifies the strength of both data sets, which are the representation of the horizontal cloud extent for the BT data and the reproduction of the cloud amount for the COSMO-EU data. The results of the analysis of both data sets show the great advantage of the cloud imager. However, because both cloud data sets do not present the complete fine structure of the real cloud fields in the atmosphere it is assumed that the results tend to underestimate the increase in information. In conclusion, real measurements by such an instrument may result in an even higher benefit for tropospheric limb retrievals.

  4. Acceleration of radiative transfer model calculations for the retrieval of trace gases under cloudy conditions

    International Nuclear Information System (INIS)

    Efremenko, Dmitry S.; Loyola, Diego G.; Spurr, Robert J.D.; Doicu, Adrian

    2014-01-01

    In the independent pixel approximation (IPA), radiative transfer computations involving cloudy scenes require two separate calls to the radiative transfer model (RTM), one call for a clear sky scenario, the other for an atmosphere containing clouds. In this paper, clouds are considered as an optically homogeneous layer. We present two novel methods for RTM performance enhancement with particular application to trace gas retrievals under cloudy conditions. Both methods are based on reusing results from clear-sky RTM calculations to speed up corresponding calculations for the cloud-filled scenario. The first approach is numerically exact, and has been applied to the discrete-ordinate with matrix exponential (DOME) RTM. Results from the original clear sky computation can be saved in the memory and reused for the non-cloudy layers in the second computation. In addition, for the whole-atmosphere boundary-value approach to the determination of the intensity field, we can exploit a ’telescoping technique’ to reduce the dimensionality (and hence the computational effort for the solution) of the boundary value problem in the absence of Rayleigh scattering contributions for higher azimuthal components of the radiation field. The second approach is (for the cloudy scenario) to generate a spectral correction applied to the radiation field from a fast two-stream RTM. This correction is based on the use of principal-component analysis (PCA) applied to a given window of spectral optical property data, in order to exploit redundancy in the data and confine the number of full-stream multiple scatter computations to the first few EOFs (Empirical Orthogonal Functions) arising from the PCA. This method has been applied to the LIDORT RTM; although the method involves some approximation, it provides accuracy better than 0.2%, and a speed-up factor of approximately 2 compared with two calls of RTM. -- Highlights: • Reusing results from clear-sky computations for a model with a

  5. Trace Dynamics and a non-commutative special relativity

    International Nuclear Information System (INIS)

    Lochan, Kinjalk; Singh, T.P.

    2011-01-01

    Trace Dynamics is a classical dynamical theory of non-commuting matrices in which cyclic permutation inside a trace is used to define the derivative with respect to an operator. We use the methods of Trace Dynamics to construct a non-commutative special relativity. We define a line-element using the Trace over space-time coordinates which are assumed to be operators. The line-element is shown to be invariant under standard Lorentz transformations, and is used to construct a non-commutative relativistic dynamics. The eventual motivation for constructing such a non-commutative relativity is to relate the statistical thermodynamics of this classical theory to quantum mechanics. -- Highlights: → Classical time is external to quantum mechanics. → This implies need for a formulation of quantum theory without classical time. → A starting point could be a non-commutative special relativity. → Such a relativity is developed here using the theory of Trace Dynamics. → A line-element is defined using the Trace over non-commuting space-time operators.

  6. Meteorology during the DOMINO campaign and its connection with trace gases and aerols

    NARCIS (Netherlands)

    Adame, J.A.; Martinez, M.; Sorribas, M.; Hidalgo, P.J.; Vilà-Guerau de Arellano, J.

    2014-01-01

    The DOMINO (Diel Oxidant Mechanisms in relation to Nitrogen Oxides) campaign was carried out from 21 November to 8 December 2008 at the El Arenosillo station (SW of Spain) in a coastal-rural environment. The main weather conditions are analysed using local meteorological variables, meteorological

  7. Progress of pharmacogenomic research related to minerals and trace elements.

    Science.gov (United States)

    Zeng, Mei-Zi; Tang, Jie; Liu, Zhao-Qian; Zhou, Hong-Hao; Zhang, Wei

    2015-10-01

    Pharmacogenomics explores the variations in both the benefits and the adverse effects of a drug among patients in a target population by analyzing genomic profiles of individual patients. Minerals and trace elements, which can be found in human tissues and maintain normal physiological functions, are also in the focus of pharmacogenomic research. Single-nucleotide polymorphisms (SNPs) affect the metabolism, disposition and efficacy of minerals and trace elements in humans, resulting in changes of body function. This review describes some of the recent progress in pharmacogenomic research related to minerals and trace elements.

  8. Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow

    Directory of Open Access Journals (Sweden)

    W. J. Massman

    2008-10-01

    Full Text Available Recent studies with closed-path eddy covariance (EC systems have indicated that the attenuation of fluctuations of water vapor concentration is dependent upon ambient relative humidity, presumably due to sorption/desorption of water molecules at the interior surface of the tube. Previous studies of EC-related tube attenuation effects have either not considered this issue at all or have only examined it superficially. Nonetheless, the attenuation of water vapor fluctuations is clearly much greater than might be expected from a passive tracer in turbulent tube flow. This study reexamines the turbulent tube flow issue for both passive and sorbing tracers with the intent of developing a physically-based semi-empirical model that describes the attenuation associated with water vapor fluctuations. Toward this end, we develop a new model of tube flow dynamics (radial profiles of the turbulent diffusivity and tube airstream velocity. We compare our new passive-tracer formulation with previous formulations in a systematic and unified way in order to assess how sensitive the passive-tracer results depend on fundamental modeling assumptions. We extend the passive tracer model to the vapor sorption/desorption case by formulating the model's wall boundary condition in terms of a physically-based semi-empirical model of the sorption/desorption vapor fluxes. Finally we synthesize all modeling and observational results into a single analytical expression that captures the effects of the mean ambient humidity and tube flow (Reynolds number on tube attenuation.

  9. Distributions of trace gases and aerosols during the dry biomass burning season in southern Africa

    Science.gov (United States)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Blake, Donald R.; Gao, Song; Kirchstetter, Thomas W.

    2003-09-01

    Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO2), ozone (O3), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO2), CO, methane (CH4), O3, black particulate carbon, and total particulate carbon were in the Botswana and Zambia sectors (388 and 392 ppmv, 369 and 453 ppbv, 1753 and 1758 ppbv, 79 and 88 ppbv, 2.6 and 5.5 μg m-3, and 13.2 and 14.3 μg m-3). This was due to intense biomass burning in Zambia and surrounding regions. The South Africa sector had the highest average concentrations of SO2, sulfate particles, and CN (5.1 ppbv, 8.3 μg m-3, and 6400 cm-3, respectively), which derived from biomass burning and electric generation plants and mining operations within this sector. Air quality in the Mozambique sector was similar to the neighboring South Africa sector. Over the arid Namibia sector there were polluted layers aloft, in which average SO2, O3, and CO mixing ratios (1.2 ppbv, 76 ppbv, and 310 ppbv, respectively) were similar to those measured over the other more polluted sectors. This was due to transport of biomass smoke from regions of widespread savanna burning in southern Angola. Average concentrations over all sectors of CO2 (386 ± 8 ppmv), CO (261 ± 81 ppbv), SO2 (2.5 ± 1.6 ppbv), O3 (64 ± 13 ppbv), black particulate carbon (2.3 ± 1.9 μg m-3), organic particulate carbon (6.2 ± 5.2 μg m-3), total particle mass (26.0 ± 4.7 μg m-3), and potassium particles (0.4 ± 0.1 μg m-3) were comparable to those in polluted, urban air. Since the majority of the measurements

  10. Emissions of trace gases and aerosols during the open combustion of biomass in the laboratory

    Energy Technology Data Exchange (ETDEWEB)

    McMeeking, Gavin R.; Kreidenweis, Sonia M.; Baker, Stephen; Carrico, Christian M.; Chow, Judith C.; Collett, Jr., Jeffrey L.; Hao, Wei Min; Holden, Amanda S.; Kirchstetter, Thomas W.; Malm, William C.; Moosmuller, Hans; Sullivan, Amy P.; Wold, Cyle E.

    2009-05-15

    We characterized the gas- and speciated aerosol-phase emissions from the open combustion of 33 different plant species during a series of 255 controlled laboratory burns during the Fire Laboratory at Missoula Experiments (FLAME). The plant species we tested were chosen to improve the existing database for U.S. domestic fuels: laboratory-based emission factors have not previously been reported for many commonly-burned species that are frequently consumed by fires near populated regions and protected scenic areas. The plants we tested included the chaparral species chamise, manzanita, and ceanothus, and species common to the southeastern US (common reed, hickory, kudzu, needlegrass rush, rhododendron, cord grass, sawgrass, titi, and wax myrtle). Fire-integrated emission factors for gas-phase CO{sub 2}, CO, CH{sub 4}, C{sub 2-4} hydrocarbons, NH{sub 3}, SO{sub 2}, NO, NO{sub 2}, HNO{sub 3} and particle-phase organic carbon (OC), elemental carbon (EC), SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Cl{sup -}, Na{sup +}, K{sup +}, and NH{sub 4}{sup +} generally varied with both fuel type and with the fire-integrated modified combustion efficiency (MCE), a measure of the relative importance of flaming- and smoldering-phase combustion to the total emissions during the burn. Chaparral fuels tended to emit less particulate OC per unit mass of dry fuel than did other fuel types, whereas southeastern species had some of the largest observed EF for total fine particulate matter. Our measurements often spanned a larger range of MCE than prior studies, and thus help to improve estimates for individual fuels of the variation of emissions with combustion conditions.

  11. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    Science.gov (United States)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~ 21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in the first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~ 20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also

  12. The impact of vibrational Raman scattering of air on DOAS measurements of atmospheric trace gases

    Science.gov (United States)

    Lampel, J.; Frieß, U.; Platt, U.

    2015-09-01

    In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. After inelastic scattering on N2 and O2 molecules, the scattered photons occur as additional intensity at a different wavelength, effectively leading to "filling-in" of both solar Fraunhofer lines and absorptions of atmospheric constituents, if the inelastic scattering happens after the absorption. Measured spectra in passive DOAS applications are typically corrected for rotational Raman scattering (RRS), also called Ring effect, which represents the main contribution to inelastic scattering. Inelastic scattering can also occur in liquid water, and its influence on DOAS measurements has been observed over clear ocean water. In contrast to that, vibrational Raman scattering (VRS) of N2 and O2 has often been thought to be negligible, but it also contributes. Consequences of VRS are red-shifted Fraunhofer structures in scattered light spectra and filling-in of Fraunhofer lines, additional to RRS. At 393 nm, the spectral shift is 25 and 40 nm for VRS of O2 and N2, respectively. We describe how to calculate VRS correction spectra according to the Ring spectrum. We use the VRS correction spectra in the spectral range of 420-440 nm to determine the relative magnitude of the cross-sections of VRS of O2 and N2 and RRS of air. The effect of VRS is shown for the first time in spectral evaluations of Multi-Axis DOAS data from the SOPRAN M91 campaign and the MAD-CAT MAX-DOAS intercomparison campaign. The measurements yield in agreement with calculated scattering cross-sections that the observed VRS(N2) cross-section at 393 nm amounts to 2.3 ± 0.4 % of the cross-section of RRS at 433 nm under tropospheric conditions. The contribution of VRS(O2) is also found to be in agreement with calculated scattering cross-sections. It is concluded, that this phenomenon has to be included in the spectral evaluation of weak absorbers as it

  13. Long term measurements of submicrometer urban aerosols: statistical analysis for correlations with meteorological conditions and trace gases

    Directory of Open Access Journals (Sweden)

    B. Wehner

    2003-01-01

    Full Text Available Long-term measurements (over 4 years of particle number size distributions (submicrometer particles, 3-800 nm in diameter, trace gases (NO, NO2, and O3, and meteorological parameters (global radiation, wind speed and direction, atmospheric pressure, etc. were taken in a moderately polluted site in the city of Leipzig (Germany. The resulting complex data set was analyzed with respect to seasonal, weekly, and diurnal variation of the submicrometer aerosol. Car traffic produced a peak in the number size distribution at around 20 nm particle diameter during morning rush hour on weekdays. A second peak at 10-15 nm particle diameter occurred around noon during summer, confirmed by high correlation between concentration of particles less than 20 nm and the global radiation. This new-particle formation at noon was correlated with the amount of global radiation. A high concentration of accumulation mode particles (between 100 and 800 nm, which are associated with large particle-surface area, might prevent this formation. Such high particle concentration in the ultrafine region (particles smaller than 20 nm in diameter was not detected in the particle mass, and thus, particle mass concentration is not suitable for determining the diurnal patterns of particles. In summer, statistical time series analysis showed a cyclic pattern of ultrafine particles with a period of one day and confirmed the correlation with global radiation. Principal component analysis (PCA revealed a strong correlation between the particle concentration for 20-800 nm particles and the NO- and NO2-concentrations, indicating the influence of combustion processes on this broad size range, in particular during winter. In addition, PCA also revealed that particle concentration depended on meteorological conditions such as wind speed and wind direction, although the dependence differed with particle size class.

  14. The effects of Southeast Asia fire activities on tropospheric ozone, trace gases and aerosols at a remote site over the Tibetan Plateau of Southwest China

    International Nuclear Information System (INIS)

    Chan, C.Y.; Wong, K.H.; Li, Y.S.; Chan, L.Y.

    2006-01-01

    Tropospheric ozone (O 3 ), carbon monoxide (CO), total reactive nitrogen (NO y ) and aerosols (PM 2.5 and PM 10 ) were measured on the southeastern Tibetan Plateau at Tengchong (25.01 deg N, 98.3 deg E, 1960 m a.s.l.) in Southwest China, where observational data is scarce, during a field campaign of the TAPTO-China (Transport of Air Pollutants and Tropospheric O 3 over China) in the spring of 2004. Fire maps derived from satellite data and backward air trajectories were used to trace the source regions and transport pathways of pollution. Ozone, CO, NO y , PM 10 and PM 2.5 had average concentrations of 26 ± 8 ppb, 179 ± 91 ppb, 2.7 ± 1.2 ppb and 34 ± 23 and 28 ± 19 μg/m 3 , respectively. The measured O 3 level is low when compared with those reported for similar longitudinal sites in Southeast (SE) Asia and northeastern Tibetan Plateau in Northwest China suggesting that there exist complex O 3 variations in the Tibetan Plateau and its neighbouring SE Asian region. High levels of pollution with hourly averages of O 3 , CO, NO y , PM 10 and PM 2.5 concentrations up to 59, 678 and 7.7 ppb and 158 and 137 μg/m 3 , respectively, were observed. The increase of pollutants in the lower troposphere was caused by regional built-up and transport of pollution from active fire regions of the SE Asia subcontinent and from northern South Asia. Our results showed that pollution transport from SE Asia and South Asia had relatively stronger impacts than that from Central and South China on the abundance of O 3 , trace gases and aerosols in the background atmosphere of the Tibetan Plateau of Southwest China

  15. Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

    Science.gov (United States)

    Gerrish, Harold C; Tessmann, Arthur M

    1935-01-01

    The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

  16. A versatile, refrigerant- and cryogen-free cryofocusing–thermodesorption unit for preconcentration of traces gases in air

    Directory of Open Access Journals (Sweden)

    F. Obersteiner

    2016-10-01

    Full Text Available We present a compact and versatile cryofocusing–thermodesorption unit, which we developed for quantitative analysis of halogenated trace gases in ambient air. Possible applications include aircraft-based in situ measurements, in situ monitoring and laboratory operation for the analysis of flask samples. Analytes are trapped on adsorptive material cooled by a Stirling cooler to low temperatures (e.g. −80 °C and subsequently desorbed by rapid heating of the adsorptive material (e.g. +200 °C. The set-up involves neither the exchange of adsorption tubes nor any further condensation or refocusing steps. No moving parts are used that would require vacuum insulation. This allows for a simple and robust design. Reliable operation is ensured by the Stirling cooler, which neither contains a liquid refrigerant nor requires refilling a cryogen. At the same time, it allows for significantly lower adsorption temperatures compared to commonly used Peltier elements. We use gas chromatography – mass spectrometry (GC–MS for separation and detection of the preconcentrated analytes after splitless injection. A substance boiling point range of approximately −80 to +150 °C and a substance mixing ratio range of less than 1 ppt (pmol mol−1 to more than 500 ppt in preconcentrated sample volumes of 0.1 to 10 L of ambient air is covered, depending on the application and its analytical demands. We present the instrumental design of the preconcentration unit and demonstrate capabilities and performance through the examination of analyte breakthrough during adsorption, repeatability of desorption and analyte residues in blank tests. Examples of application are taken from the analysis of flask samples collected at Mace Head Atmospheric Research Station in Ireland using our laboratory GC–MS instruments and by data obtained during a research flight with our in situ aircraft instrument GhOST-MS (Gas chromatograph for the Observation of Tracers

  17. A research program on radiative, chemical, and dynamical feedback progresses influencing the carbon dioxide and trace gases climate effects

    International Nuclear Information System (INIS)

    1989-07-01

    This report summarizes the up-to-date progress. The program includes two tasks: atmospheric radiation and climatic effects and their objective is to link quantitatively the radiation forcing changes and the climate responses caused by increasing greenhouse gases. Here, the objective and approach are described. We investigate the combined atmospheric radiation characteristics of the greenhouse gases (H 2 O, CO 2 , CH 4 , N 2 O, CFCs, and O 3 ), aerosols and clouds. Since the climatic effect of increasing atmospheric greenhouse gases is initiated by perturabtion to the longwave thermal radiation, it is critical to understand better the radiation characteristics of the greenhouse gases and their relationship to radiatively-important aerosols and clouds; the latter reflect solar radiation (a cooling of the surface) and provide a greenhouse effect (a warming to the surface). Therefore, aerosol and cloud particles are an integral part of the radiation field in the atmosphere. 9 refs

  18. Field Measurements of Trace Gases and Aerosols Emitted by Undersampled Combustion Sources Including Wood and Dung Cooking Fires, Garbage and Crop Residue Burning, and Indonesian Peat Fires

    Science.gov (United States)

    Stockwell, C.; Jayarathne, T. S.; Goetz, D.; Simpson, I. J.; Selimovic, V.; Bhave, P.; Blake, D. R.; Cochrane, M. A.; Ryan, K. C.; Putra, E. I.; Saharjo, B.; Stone, E. A.; DeCarlo, P. F.; Yokelson, R. J.

    2017-12-01

    Field measurements were conducted in Nepal and in the Indonesian province of Central Kalimantan to improve characterization of trace gases and aerosols emitted by undersampled combustion sources. The sources targeted included cooking with a variety of stoves, garbage burning, crop residue burning, and authentic peat fires. Trace gas and aerosol emissions were studied using a land-based Fourier transform infrared spectrometer, whole air sampling, photoacoustic extinctiometers (405 and 870nm), and filter samples that were analyzed off-line. These measurements were used to calculate fuel-based emission factors (EFs) for up to 90 gases, PM2.5, and PM2.5 constituents. The aerosol optical data measured included EFs for the scattering and absorption coefficients, the single scattering albedo (at 870 and 405 nm), as well as the absorption Ångström exponent. The emissions varied significantly by source, although light absorption by both brown and black carbon (BrC and BC, respectively) was important for all non-peat sources. For authentic peat combustion, the emissions of BC were negligible and absorption was dominated by organic aerosol. The field results from peat burning were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat and compare well to the limited data available from other field studies. The EFs can be used with estimates of fuel consumption to improve regional emissions inventories and assessments of the climate and health impacts of these undersampled sources.

  19. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    Directory of Open Access Journals (Sweden)

    I. R. Burling

    2011-12-01

    Full Text Available We have measured emission factors for 19 trace gas species and particulate matter (PM2.5 from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

  20. Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

    Science.gov (United States)

    Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

    2014-01-01

    Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

  1. First results of the observations of trace gases in the Martian atmosphere by the Planetary Fourier Spectrometer onboard the Mars Express

    Science.gov (United States)

    Titov, D. V.; Ignatiev, N.; Formisano, V.; Grassi, D.; Giuranna, M.; Maturilli, A.; Piccioni, G.; Moroz, V. I.; Lellouch, E.; Encrenaz, T.; Pfs Team

    High spectral resolution observations of Mars by the PFS/Mars Express provide new insight into the atmospheric composition. Spectral features of atmospheric CO2 and its isotopes at 15, 4.3, 2.7, 1.4 μ m, CO at 4.7 and 2.35 μ m, and H2O at 40, 2.56, and 1.38 μ m as well as solar spectral features are clearly identified in the PFS spectra. HDO spectral details at 3.7 μ m were also tentatively detected. The paper will present qualitative and quantitative analysis of the PFS spectra in the regions of spectral bands of trace gases. Abundance of minor constituents will be determined using complete radiative transfer modeling including possible non-LTE effects. We will also present results of search for other minor species with emphasis on the limb observations that provide higher air mass factor.

  2. Trace gases, aerosols and their interactions with synoptic weather: An overview of in-situ measurements at the SORPES Station in the western Yangtze River Delta, China

    Science.gov (United States)

    Ding, A.; Fu, C.; Yang, X.; Petaja, T.; Kerminen, V.; Kulmala, M. T.

    2013-12-01

    This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5pollution in this region. Case studies for typical O3 and PM2.5 episodes showed that synoptic weather played an important role in air pollution, especially for O3. Observation during the typical biomass burning seasons also shows clear air pollution - weather interactions. For the typical episode occurred on 10 June, 2012, the measurement suggest that the mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease of solar radiation by more than 70 %, of sensible heat flux over 85 %, a temperature drop by almost 10 K, and a change 10 of rainfall during daytime and nighttime. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions, and

  3. Chiral trace relations in Ω-deformed N=2 theories

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento, Via Arnesano, 73100 Lecce (Italy); INFN - Sezione di LecceVia Arnesano, 73100 Lecce (Italy)

    2017-05-04

    We consider N=2SU(2) gauge theories in four dimensions (pure or mass deformed) and discuss the properties of the simplest chiral observables in the presence of a generic Ω-deformation. We compute them by equivariant localization and analyze the structure of the exact instanton corrections to the classical chiral ring relations. We predict exact relations valid at all instanton number among the traces 〈Trφ{sup n}〉, where φ is the scalar field in the gauge multiplet. In the Nekrasov-Shatashvili limit, such relations may be explained in terms of the available quantized Seiberg-Witten curves. Instead, the full two-parameter deformation enjoys novel features and the ring relations require non trivial additional derivative terms with respect to the modular parameter. Higher rank groups are briefly discussed emphasizing non-factorization of correlators due to the Ω-deformation. Finally, the structure of the deformed ring relations in the N=2{sup ⋆} theory is analyzed from the point of view of the Alday-Gaiotto-Tachikawa correspondence proving consistency as well as some interesting universality properties.

  4. EDDY RESOLVING NUTRIENT ECODYNAMICS IN THE GLOBAL PARALLEL OCEAN PROGRAM AND CONNECTIONS WITH TRACE GASES IN THE SULFUR, HALOGEN AND NMHC CYCLES

    Energy Technology Data Exchange (ETDEWEB)

    S. CHU; S. ELLIOTT

    2000-08-01

    Ecodynamics and the sea-air transfer of climate relevant trace gases are intimately coupled in the oceanic mixed layer. Ventilation of species such as dimethyl sulfide and methyl bromide constitutes a key linkage within the earth system. We are creating a research tool for the study of marine trace gas distributions by implementing coupled ecology-gas chemistry in the high resolution Parallel Ocean Program (POP). The fundamental circulation model is eddy resolving, with cell sizes averaging 0.15 degree (lat/long). Here we describe ecochemistry integration. Density dependent mortality and iron geochemistry have enhanced agreement with chlorophyll measurements. Indications are that dimethyl sulfide production rates must be adjusted for latitude dependence to match recent compilations. This may reflect the need for phytoplankton to conserve nitrogen by favoring sulfurous osmolytes. Global simulations are also available for carbonyl sulfide, the methyl halides and for nonmethane hydrocarbons. We discuss future applications including interaction with atmospheric chemistry models, high resolution biogeochemical snapshots and the study of open ocean fertilization.

  5. Measurement of gas/water uptake coefficients for trace gases active in the marine environment. [Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Davidovits, P. [Boston Coll., Chestnut Hill, MA (United States). Dept. of Chemistry; Worsnop, D.W.; Zahniser, M.S.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

    1992-02-01

    Ocean produced reduced sulfur compounds including dimethylsulfide (DMS), hydrogen sulfide (H{sub 2}S), carbon disulfide (CS{sub 2}), methyl mercaptan (CH{sub 3}CH) and carbonyl sulfide (OCS) deliver a sulfur burden to the atmosphere which is roughly equal to sulfur oxides produced by fossil fuel combustion. These species and their oxidation products dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO{sub 2}) and methane sulfonic acid (MSA) dominate aerosol and CCN production in clean marine air. Furthermore, oxidation of reduced sulfur species will be strongly influenced by NO{sub x}/O{sub 3} chemistry in marine atmospheres. The multiphase chemical processes for these species must be understood in order to study the evolving role of combustion produced sulfur oxides over the oceans. We have measured the chemical and physical parameters affecting the uptake of reduced sulfur compounds, their oxidation products, ozone, and nitrogen oxides by the ocean`s surface, and marine clouds, fogs, and aerosols. These parameters include: gas/surface mass accommodation coefficients; physical and chemically modified (effective) Henry`s law constants; and surface and liquid phase reaction constants. These parameters are critical to understanding both the interaction of gaseous trace species with cloud and fog droplets and the deposition of trace gaseous species to dew covered, fresh water and marine surfaces.

  6. Emissions of trace gases from Australian temperate forest fires: emission factors and dependence on modified combustion efficiency

    Science.gov (United States)

    Guérette, Elise-Andrée; Paton-Walsh, Clare; Desservettaz, Maximilien; Smith, Thomas E. L.; Volkova, Liubov; Weston, Christopher J.; Meyer, Carl P.

    2018-03-01

    We characterised trace gas emissions from Australian temperate forest fires through a mixture of open-path Fourier transform infrared (OP-FTIR) measurements and selective ion flow tube mass spectrometry (SIFT-MS) and White cell FTIR analysis of grab samples. We report emission factors for a total of 25 trace gas species measured in smoke from nine prescribed fires. We find significant dependence on modified combustion efficiency (MCE) for some species, although regional differences indicate that the use of MCE as a proxy may be limited. We also find that the fire-integrated MCE values derived from our in situ on-the-ground open-path measurements are not significantly different from those reported for airborne measurements of smoke from fires in the same ecosystem. We then compare our average emission factors to those measured for temperate forest fires elsewhere (North America) and for fires in another dominant Australian ecosystem (savanna) and find significant differences in both cases. Indeed, we find that although the emission factors of some species agree within 20 %, including those of hydrogen cyanide, ethene, methanol, formaldehyde and 1,3-butadiene, others, such as acetic acid, ethanol, monoterpenes, ammonia, acetonitrile and pyrrole, differ by a factor of 2 or more. This indicates that the use of ecosystem-specific emission factors is warranted for applications involving emissions from Australian forest fires.

  7. Application of Gauss's theorem to quantify localized surface emissions from airborne measurements of wind and trace gases

    Science.gov (United States)

    Conley, Stephen; Faloona, Ian; Mehrotra, Shobhit; Suard, Maxime; Lenschow, Donald H.; Sweeney, Colm; Herndon, Scott; Schwietzke, Stefan; Pétron, Gabrielle; Pifer, Justin; Kort, Eric A.; Schnell, Russell

    2017-09-01

    Airborne estimates of greenhouse gas emissions are becoming more prevalent with the advent of rapid commercial development of trace gas instrumentation featuring increased measurement accuracy, precision, and frequency, and the swelling interest in the verification of current emission inventories. Multiple airborne studies have indicated that emission inventories may underestimate some hydrocarbon emission sources in US oil- and gas-producing basins. Consequently, a proper assessment of the accuracy of these airborne methods is crucial to interpreting the meaning of such discrepancies. We present a new method of sampling surface sources of any trace gas for which fast and precise measurements can be made and apply it to methane, ethane, and carbon dioxide on spatial scales of ˜ 1000 m, where consecutive loops are flown around a targeted source region at multiple altitudes. Using Reynolds decomposition for the scalar concentrations, along with Gauss's theorem, we show that the method accurately accounts for the smaller-scale turbulent dispersion of the local plume, which is often ignored in other average mass balance methods. With the help of large eddy simulations (LES) we further show how the circling radius can be optimized for the micrometeorological conditions encountered during any flight. Furthermore, by sampling controlled releases of methane and ethane on the ground we can ascertain that the accuracy of the method, in appropriate meteorological conditions, is often better than 10 %, with limits of detection below 5 kg h-1 for both methane and ethane. Because of the FAA-mandated minimum flight safe altitude of 150 m, placement of the aircraft is critical to preventing a large portion of the emission plume from flowing underneath the lowest aircraft sampling altitude, which is generally the leading source of uncertainty in these measurements. Finally, we show how the accuracy of the method is strongly dependent on the number of sampling loops and/or time

  8. Evaluation of organical fertilizers in relation to minimalization of air polution by greenhouse gases and amonia

    Directory of Open Access Journals (Sweden)

    Patrik Burg

    2006-01-01

    Full Text Available Agricultural production presents one of the biggest producers of greenhouse gases. Between the most significant belongs carbon dioxide (CO2, methane (CH4, nitrous oxide (N2O, ozon (O3 and hydrogen sulphide (H2S. The work deals with classification of quantity by liberate emissions in relation to different variants of fertilization by cultivation of horticultural crops (head cabbage. For the metering was exploited gas analyzer INNOVA 1312. The results demonstrate significant difference between experimental variants by quantity of liberate emission, but also in the height of production.

  9. An 18 Moments Model for Dense Gases: Entropy and Galilean Relativity Principles without Expansions

    Directory of Open Access Journals (Sweden)

    M. Cristina Carrisi

    2015-01-01

    Full Text Available The 14 moments model for dense gases, introduced in the last few years by Arima, Taniguchi, Ruggeri and Sugiyama, is here extended up to 18 moments. They have found the closure of the balance equations up to a finite order with respect to equilibrium; it is also possible to impose for that model the entropy and Galilean relativity principles up to whatever order with respect to equilibrium, but by using Taylor’s expansion. Here, the exact solution is found, without expansions, but a bigger number of moments has to be considered and reasons will be shown suggesting that this number is at least 18.

  10. Influence of modelled soil biogenic NO emissions on related trace gases and the atmospheric oxidizing capacity

    NARCIS (Netherlands)

    Steinkamp, J.; Ganzeveld, L.N.; Wilcke, W.; Lawrence, M.G.

    2009-01-01

    The emission of nitric oxide (NO) by soils (SNOx) is an important source of oxides of nitrogen (NOx=NO+NO2) in the troposphere, with estimates ranging from 4 to 21 Tg of nitrogen per year. Previous studies have examined the influence of SNOx on ozone (O-3) chemistry. We employ the ECHAM5/MESSy

  11. Global satellite analysis of the relation between aerosols and short-lived trace gases

    NARCIS (Netherlands)

    Veefkind, J.P.; Boersma, K.F.; Wang, J.; Kurosu, T.; Chance, K.; Krotkov, N.A.; Levelt, P.F.

    2011-01-01

    The spatial and temporal correlations between concurrent satellite observations of aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) and tropospheric columns of nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) from the Ozone

  12. Medical and health-related trace element analysis by TXRF

    International Nuclear Information System (INIS)

    Greaves, E.D.

    2000-01-01

    The advantages offered with TXRF analysis by direct irradiation with monochromatic X-rays of tissue homogenates and body fluids make the technique appropriate for a number of medical and health related applications. The ability to detect low levels of toxic heavy elements is being used as an aid in accidental poisoning diagnosis and treatment, in treatment-induced toxicity control and as an accessory in medical and health research. Thus lead-in-whole-blood analysis is used in confirmation of diagnosis of victims of poisoning, or monitoring the evolution and efficiency of the clinical treatment. Measurement and control of plasma platinum levels of cancer patients undergoing chemotherapy with Pt-containing drugs includes: establishment of the drug level-tumor remission response, measurement of Pt plasma level curves and establishment of optimum dosage to minimize the nephrotoxicity of platinum, and bioequivalence comparisons of different commercially available platinum containing anticancer drugs. Analysis as an aid in clinical research applications includes: trace element determination of amniotic fluid in fetus malformation studies; analysis of brain specimens and cerebrospinal fluid in diagnosis of central nervous system disorders; the influence of trace elements in cataract genesis and the influence of heavy elements in semen quality in human reproduction studies. Human body samples require the use of monochromatized beams of x-rays in order to derive the special advantage of its use: i) The reduction in the spectrum background allowing direct irradiation of organic matter specimens. Hence human tissue and body fluids are prepared by simple procedures involving dilution, homogenization and standard addition avoiding the need for specimen digestion. This results in faster, cheaper methods that decrease sample contamination problems. ii) The presence of a large Compton scattered signal in the spectrum and its use as an internal standard reference allows further

  13. Field measurements of trace gases and aerosols emitted by peat fires in Central Kalimantan, Indonesia, during the 2015 El Niño

    Directory of Open Access Journals (Sweden)

    C. E. Stockwell

    2016-09-01

    Full Text Available Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional–global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm, and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs; grams of a compound per kilogram biomass burned for up to  ∼  90 gases, including CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc. The modified combustion efficiency (MCE of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n  =  35, indicating essentially pure smoldering combustion, and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g kg−1 were carbon dioxide (1564 ± 77, carbon monoxide (291 ± 49, methane (9.51 ± 4.74, hydrogen cyanide (5.75 ± 1.60, acetic acid (3.89 ± 1.65, ammonia (2.86 ± 1.00, methanol (2.14 ± 1.22, ethane (1.52 ± 0.66, dihydrogen (1.22 ± 1.01, propylene (1.07 ± 0.53, propane (0.989 ± 0.644, ethylene (0.961 ± 0.528, benzene (0.954 ± 0.394, formaldehyde (0.867 ± 0.479, hydroxyacetone (0.860 ± 0.433, furan (0.772 ± 0.035, acetaldehyde

  14. Robust IR Remote Sensing Technique of the Total Column of Trace Gases Including Carbon Dioxide and Methane

    Science.gov (United States)

    Georgieva, E. M.; Heaps, W. S.

    2011-01-01

    methane very suddenly further exacerbating climate change [2]. Last year our group began a joint effort with Johns Hopkins Applied Physics Laboratory to investigate the possibility of developing a small unmanned aerial vehicle (UAV) equipped to measure greenhouse gases-particularly methane. Although we are targeting our system for smaller UAV's the instrument will be directly applicable to missions involving larger NASA UAV's such as Global Hawk or even on missions utilizing manned aircraft. Because of its small size, inherent ruggedness and simplicity some version of our proposed instrument may find a role as a satellite instrument for NASA or NOAA.

  15. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis Part II: evaluation of measured and modeled trace gases and particle size distributions

    Directory of Open Access Journals (Sweden)

    C. Ochoa

    2012-11-01

    Full Text Available This study extends the work of Baumgardner et al. (2009 in which measurements of trace gases and particles, at a remote, high altitude mountain site, 60 km from Mexico City were analyzed with respect to the origin of the air masses. In the current evaluation, the temperature, water vapor mixing ratio (WMR, ozone (O3, carbon monoxide (CO, sulfur dioxide (SO2 and acyl peroxy nitrate (APN are simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. Comparisons between the model and measurements are also evaluated for particle size distributions (PSDs of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM. The model predictions of the diurnal trends in temperature, WMR and trace gases were generally well correlated; 13 of the 18 correlations were significant at a confidence level of <0.01. Less satisfactory were the average hourly differences between model and measurements that showed predicted values within expected, natural variation for only 10 of the 18 comparisons. The model performed best when comparing with the measurements during periods when the air originated from the east. In that case all six of the parameters being compared had average differences between the model and measurements less than the expected standard deviation. For the cases when the air masses are from the southwest or west northwest, only two of the comparisons from each case showed differences less than the expected standard deviation. The differences appear to be a result of an overly rapid growth of the boundary layer predicted by the model and too much dilution. There also is more O3 being produced, most likely by photochemical production, downwind of the emission sources than is predicted by the model.

    The measured and modeled PSD compare very well with respect to their general shape and the diameter of the peak concentrations. The spectra are log

  16. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2013-01-01

    Full Text Available An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5 emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC, organic carbon (OC, and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS, proton-transfer ion-trap mass spectrometry (PIT-MS, negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS, and gas chromatography with MS detection (GC-MS. 204 trace gas species (mostly non-methane organic compounds (NMOC were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species.

    In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5 was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for

  17. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Energy Technology Data Exchange (ETDEWEB)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker III, D. R.; Jung, H.; Weise, D. R.

    2013-01-01

    Vegetative fuels commonly consumed in prescribed fires were collected from five locations in the southeastern and southwestern U.S. and burned in a series of 77 fires at the U.S. Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. An additional 152 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. As phase II of this study, we conducted airborne and ground-based sampling of the emissions from real prescribed fires mostly in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These extensive field measurements of emission factors (EF) for temperate biomass burning are useful both for modeling and to examine the representativeness of our lab fire EF. The lab/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for “smoldering compounds” emitted by burning the semi

  18. Influence of local emissions on concentration and isotopic composition of trace gases (CO2 and CH4) under strong anthropopression: A case study from Krakow, southern Poland

    International Nuclear Information System (INIS)

    Florkowski, T.; Korus, A.; Kuc, T.; Lasa, J.; Necki, J.M.; Zimnoch, M.

    2002-01-01

    Full text: Measurements of the isotopic composition of carbon dioxide and methane together with their concentrations in the atmosphere, yield useful information on the contribution of anthropogenic sources to regional budgets of these gases and their seasonal changes. Observed correlation between isotopic composition and inverse concentration of these gases is used for estimation of mean isotopic composition of the local source. Monitoring of atmospheric CO 2 has been initiated in Krakow in 1982. The sampling point is located in a polluted urban area with strong contribution of anthropogenic gases originating both from local sources (coal burning, car traffic, leakages from city gas network, landfills) and large distant emitters - industrial district located ca. 80 km to the west from Krakow (Silesia district). Quasi-continuous measurements of CO 2 , and CH 4 concentrations in the low atmosphere are performed using gas chromatographic method. For isotope measurements, the atmospheric CO 2 is continuously sampled by sorption on molecular sieve in be-weekly intervals and radiocarbon concentration is measured by liquid scintillation spectrometer, while δ 13 C is determined by isotope ratio mass spectrometer. Measurement error (1σ for single measurement) is in the order of 0.1 ppm for CO 2 concentration, ±8 per mille for δ 14 C, and ± 0.1 per mille for δ 13 C. In 1994, a new station for regular observations of greenhouse gases in lower atmosphere was set up in the High Tatra mountains, at Kasprowy Wierch (49 deg. N, 20 deg. E, 1980 m a.s.l., 300 m above the tree line). Kasprowy Wierch, with only small influences from local sources of trace gases can be considered as a reference station for this region of Poland. The record of CO 2 and CH 4 concentration and their isotope composition obtained at Kasprowy Wierch is considered as a background level for Krakow observations. The presented study was aimed at better characterisation and quantification of the local

  19. Effects of land use on surface–atmosphere exchanges of trace gases and energy in Borneo: comparing fluxes over oil palm plantations and a rainforest

    Science.gov (United States)

    Fowler, David; Nemitz, Eiko; Misztal, Pawel; Di Marco, Chiara; Skiba, Ute; Ryder, James; Helfter, Carole; Cape, J. Neil; Owen, Sue; Dorsey, James; Gallagher, Martin W.; Coyle, Mhairi; Phillips, Gavin; Davison, Brian; Langford, Ben; MacKenzie, Rob; Muller, Jennifer; Siong, Jambery; Dari-Salisburgo, Cesare; Di Carlo, Piero; Aruffo, Eleonora; Giammaria, Franco; Pyle, John A.; Hewitt, C. Nicholas

    2011-01-01

    This paper reports measurements of land–atmosphere fluxes of sensible and latent heat, momentum, CO2, volatile organic compounds (VOCs), NO, NO2, N2O and O3 over a 30 m high rainforest canopy and a 12 m high oil palm plantation in the same region of Sabah in Borneo between April and July 2008. The daytime maximum CO2 flux to the two canopies differs by approximately a factor of 2, 1200 mg C m−2 h−1 for the oil palm and 700 mg C m−2 h−1 for the rainforest, with the oil palm plantation showing a substantially greater quantum efficiency. Total VOC emissions are also larger over the oil palm than over the rainforest by a factor of 3. Emissions of isoprene from the oil palm canopy represented 80 per cent of the VOC emissions and exceeded those over the rainforest in similar light and temperature conditions by on average a factor of 5. Substantial emissions of estragole (1-allyl-4-methoxybenzene) from the oil palm plantation were detected and no trace of this VOC was detected in or above the rainforest. Deposition velocities for O3 to the rainforest were a factor of 2 larger than over oil palm. Emissions of nitrous oxide were larger from the soils of the oil palm plantation than from the soils of the rainforest by approximately 25 per cent. It is clear from the measurements that the large change in the species composition generated by replacing rainforest with oil palm leads to profound changes in the net exchange of most of the trace gases measured, and thus on the chemical composition of the boundary layer over these surfaces. PMID:22006962

  20. Observations of tropospheric trace gases and meteorology in rural Virginia using an unattended monitoring system: Hurricane Hugo (1989), A case study

    Science.gov (United States)

    Doddridge, Bruce G.; Dickerson, Russell R.; Holland, Joshua Z.; Cooper, James N.; Wardell, R. Glenn; Poulida, Olga; Watkins, James G.

    1991-05-01

    Tropospheric trace gases such as ozone and reactive nitrogen compounds exert a strong influence on global climate, but observations of these species are limited by the necessity of having a trained observer on site to monitor instruments. A technique using modern communications technology has been developed to transport and review data collected at a remote site. The site was equipped with a PAM II station and satellite data link so that raw, real-time data and equipment status were available for inspection readily on a workstation at the University of Maryland campus through a combination of wide and local area networks. CO, NO, NOy, O3, UV radiative flux, and meteorological parameters were measured in rural Virginia for a full year. The cleanest air observed over the year was associated with the passage of Hurricane Hugo over the mid-Atlantic region on September 22, 1989. Hourly average data for concentrations of CO, NOy, and O3 observed during this particular case study were as low as 90 ppbv, 570 pptv, and 11 ppbv, respectively. Within this period, daytime NO was highly variable, ranging between the detection limit of the instrument, ˜ 20 pptv, and 2.4 ppbv. These concentrations are well below the hourly concentration average at this site for these species during September 1989. Equivalent potential temperature, θe, in conjunction with the trace gas concentrations and geostrophic back-trajectories, illustrates how this hurricane influenced air parcel history; observed concentrations of CO and NOy increased with the time the air parcel spent over land. Observations at this site were consistent with current hurricane models based on mean soundings and aircraft flights. Hurricanes over land also appear to redistribute air vertically throughout the troposphere, creating the potential for substantial post-storm tropospheric column O3 increase.

  1. Emerging catalytic technologies related to the denoxing of waste gases from thermal power stations

    International Nuclear Information System (INIS)

    Busca, G.

    2002-01-01

    The emerging catalytic technologies related to the DeNOxing of waste gases from thermal power stations are briefly discussed. In the case of the Selective Catalytic Reduction of NO x with hydrocarbons new zeolite-based or metal oxide catalytic systems are under development, whose stability and performances approach more and more those needed for a commercial process. The processes for the low temperature Selective Catalytic Reduction of NO x with ammonia are apparently promising allowing a possible application in a tail-end process configuration, at least after a total abatement of SO x . The processes of combined abatement of NO x and dioxins are already applied industrially. Also the Selective Oxidation of ammonia slip to nitrogen is already proposed as commercial process. In both last cases, however, few information is available in the open literature [it

  2. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from fuels common in the US

    Science.gov (United States)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-12-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern US. A gas chromatograph-mass spectrometry (GC-MS) instrument provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectroscopy (OP-FTIR) instrument and three different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the US Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana and were used as the basis for a number of emission factors reported by Yokelson et al. (2013). The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the three geographic fuel regions being simulated. Discrete emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 % ± 0.12 % of emissions by mole and less than 0.95 % × 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 41-54 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde

  3. Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States

    Science.gov (United States)

    Gilman, J. B.; Lerner, B. M.; Kuster, W. C.; Goldan, P. D.; Warneke, C.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2015-08-01

    A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern United States. A gas chromatograph-mass spectrometer (GC-MS) provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectrometer (OP-FTIR) and 3 different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the U.S. Department of Agriculture's Fire Sciences Laboratory in Missoula, Montana. The relative magnitude and composition of the gases emitted varied by individual fuel type and, more broadly, by the 3 geographic fuel regions being simulated. Emission ratios relative to carbon monoxide (CO) were used to characterize the composition of gases emitted by mass; reactivity with the hydroxyl radical, OH; and potential secondary organic aerosol (SOA) precursors for the 3 different US fuel regions presented here. VOCs contributed less than 0.78 ± 0.12 % of emissions by mole and less than 0.95 ± 0.07 % of emissions by mass (on average) due to the predominance of CO2, CO, CH4, and NOx emissions; however, VOCs contributed 70-90 (±16) % to OH reactivity and were the only measured gas-phase source of SOA precursors from combustion of biomass. Over 82 % of the VOC emissions by mole were unsaturated compounds including highly reactive alkenes and aromatics and photolabile oxygenated VOCs (OVOCs) such as formaldehyde. OVOCs contributed 57-68 % of the VOC mass emitted, 42-57 % of VOC-OH reactivity, and aromatic-OVOCs such as benzenediols, phenols, and benzaldehyde were the dominant potential SOA precursors. In addition, ambient air measurements of emissions from the Fourmile Canyon Fire

  4. A review of accidents, prevention and mitigation options related to hazardous gases

    International Nuclear Information System (INIS)

    Fthenakis, V.M.

    1993-05-01

    Statistics on industrial accidents are incomplete due to lack of specific criteria on what constitutes a release or accident. In this country, most major industrial accidents were related to explosions and fires of flammable materials, not to releases of chemicals into the environment. The EPA in a study of 6,928 accidental releases of toxic chemicals revealed that accidents at stationary facilities accounted for 75% of the total number of releases, and transportation accidents for the other 25%. About 7% of all reported accidents (468 cases) resulted in 138 deaths and 4,717 injuries ranging from temporary respiratory problems to critical injuries. In-plant accidents accounted for 65% of the casualties. The most efficient strategy to reduce hazards is to choose technologies which do not require the use of large quantities of hazardous gases. For new technologies this approach can be implemented early in development, before large financial resources and efforts are committed to specific options. Once specific materials and options have been selected, strategies to prevent accident initiating events need to be evaluated and implemented. The next step is to implement safety options which suppress a hazard when an accident initiating event occurs. Releases can be prevented or reduced with fail-safe equipment and valves, adequate warning systems and controls to reduce and interrupt gas leakage. If an accident occurs and safety systems fail to contain a hazardous gas release, then engineering control systems will be relied on to reduce/minimize environmental releases. As a final defensive barrier, the prevention of human exposure is needed if a hazardous gas is released, in spite of previous strategies. Prevention of consequences forms the final defensive barrier. Medical facilities close by that can accommodate victims of the worst accident can reduce the consequences of personnel exposure to hazardous gases

  5. Agricultural Fires in the Southeastern U.S. During SEAC4RS: Emissions of Trace Gases and Particles and Evolution of Ozone, Reactive Nitrogen, and Organic Aerosol

    Science.gov (United States)

    Liu, X.; Zhang, Y.; Huey, L. G.; Yokelson, R. J.; Wang, Y.; Jimenez, J. L.; Campuzano-Jost, P.; Beyersdorf, A. J.; Blake, D. R.; Choi, Y.; hide

    2016-01-01

    Emissions from 15 agricultural fires in the southeastern U.S. were measured from the NASA DC-8 research aircraft during the summer 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign. This study reports a detailed set of emission factors (EFs) for 25 trace gases and 6 fine particle species. The chemical evolution of the primary emissions in seven plumes was examined in detail for 1.2 h. A Lagrangian plume cross-section model was used to simulate the evolution of ozone (O3), reactive nitrogen species, and organic aerosol (OA). Observed EFs are generally consistent with previous measurements of crop residue burning, but the fires studied here emitted high amounts of SO2 and fine particles, especially primary OA and chloride. Filter-based measurements of aerosol light absorption implied that brown carbon (BrC) was ubiquitous in the plumes. In aged plumes, rapid production of O3, peroxyacetyl nitrate (PAN), and nitrate was observed with (Delta)O3/(Delta)CO, (Delta)PAN/(Delta)NOy, and (Delta)nitrate/(Delta)NOy reaching approx. 0.1, approx. 0.3, and approx.0.3. For five selected cases, the model reasonably simulated O3 formation but underestimated PAN formation. No significant evolution of OA mass or BrC absorption was observed. However, a consistent increase in oxygen-to-carbon (O/C) ratios of OA indicated that OA oxidation in the agricultural fire plumes was much faster than in urban and forest fire plumes. Finally, total annual SO2, NOx, and CO emissions from agricultural fires in Arkansas, Louisiana, Mississippi, and Missouri were estimated (within a factor of approx. 2) to be equivalent to approx. 2% SO2 from coal combustion and approx. 1% NOx and approx. 9% CO from mobile sources.

  6. Polymeric membrane materials: new aspects of empirical approaches to prediction of gas permeability parameters in relation to permanent gases, linear lower hydrocarbons and some toxic gases.

    Science.gov (United States)

    Malykh, O V; Golub, A Yu; Teplyakov, V V

    2011-05-11

    Membrane gas separation technologies (air separation, hydrogen recovery from dehydrogenation processes, etc.) use traditionally the glassy polymer membranes with dominating permeability of "small" gas molecules. For this purposes the membranes based on the low free volume glassy polymers (e.g., polysulfone, tetrabromopolycarbonate and polyimides) are used. On the other hand, an application of membrane methods for VOCs and some toxic gas recovery from air, separation of the lower hydrocarbons containing mixtures (in petrochemistry and oil refining) needs the membranes with preferable penetration of components with relatively larger molecular sizes. In general, this kind of permeability is characterized for rubbers and for the high free volume glassy polymers. Data files accumulated (more than 1500 polymeric materials) represent the region of parameters "inside" of these "boundaries." Two main approaches to the prediction of gas permeability of polymers are considered in this paper: (1) the statistical treatment of published transport parameters of polymers and (2) the prediction using model of ≪diffusion jump≫ with consideration of the key properties of the diffusing molecule and polymeric matrix. In the frames of (1) the paper presents N-dimensional methods of the gas permeability estimation of polymers using the correlations "selectivity/permeability." It is found that the optimal accuracy of prediction is provided at n=4. In the frames of the solution-diffusion mechanism (2) the key properties include the effective molecular cross-section of penetrating species to be responsible for molecular transportation in polymeric matrix and the well known force constant (ε/k)(eff i) of {6-12} potential for gas-gas interaction. Set of corrected effective molecular cross-section of penetrant including noble gases (He, Ne, Ar, Kr, Xe), permanent gases (H(2), O(2), N(2), CO), ballast and toxic gases (CO(2), NO(,) NO(2), SO(2), H(2)S) and linear lower hydrocarbons (CH(4

  7. PIXE analysis of caries related trace elements in tooth enamel

    International Nuclear Information System (INIS)

    Annegarn, H.J.; Jodaikin, A.; Cleaton-Jones, P.E.; Sellschop, J.P.F.; Madiba, C.C.P.; Bibby, D.; University of the Witwatersrand, Johannesburg

    1981-01-01

    PIXE analysis has been applied to a set of twenty human teeth to determine trace element concentration in enamel from areas suceptible to dental caries (mesial and distal contact points) and in areas less susceptible to the disease (buccal surface), with the aim of determining the possible roles of trace elements in the carious process. The samples were caries-free anterior incisors extracted for periodontal reasons from subjects 10-30 years of age. Prior to extraction of the sample teeth, a detailed dental history and examination was carried out in each individual. PIXE analysis, using a 3 MeV proton beam of 1 mm diameter, allowed the determination of Ca, Mn, Fe, Cu, Zn, Sr and Pb above detection limits. As demonstrated in this work, the enhanced sensitivity of PIXE analysis over electron microprobe analysis, and capability of localised surface analysis compared with the pooled samples require for neutron activation analysis, makes it a powerful and useful technique in dental analysis. (orig.)

  8. Relation between tobacco trace metals and soil type in Lebanon

    International Nuclear Information System (INIS)

    SLIM, K.; Saad, Z.; Kazpard, V.; El Samarani, A; Nabhan, Ph.

    2006-01-01

    The aim of study was to determine the concentration of nutrients in soil and tobacco samples from different agricultural regions. We studied the influence of soil type on tobacco quality and the transfer and accumulation of trace metals in tobacco leaves. The results showed that human activities in the Nabatiyeh region had a none pronounced effect on one agricultural plot than on its neighbor. The transfer factor of elements between soil and tobacco plants showed that major constituents are leached and absorbed from the soil, whereas some trace elements are finely absorbed from the alkaline soil. Statistical analysis of the micro nutrients in soil and plants confirmed the existence of two principal factors that control the distribution of elements in different compartments. Four tobacco plots in different regions were also studied as a functions of their pedologic and geologic characteristics. The major elements varied in all regions, but were always ordered Ca > Mg > Na > K. The highest transfer factor for nutrients was found in young soil layers. In the Akkar region, clay nutrients form complexes with micronutrients. Thereby reducing their absorption by tobacco plants. (author)

  9. PIXE analysis of caries related trace elements in tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Annegarn, H J; Jodaikin, A; Cleaton-Jones, P E; Sellschop, J P.F.; Madiba, C C.P.; Bibby, D [University of the Witwatersrand, Johannesburg (South Africa). Nuclear Physics Research Unit; University of the Witwatersrand, Johannesburg (South Africa). Dental Research Unit)

    1981-03-01

    PIXE analysis has been applied to a set of twenty human teeth to determine trace element concentration in enamel from areas suceptible to dental caries (mesial and distal contact points) and in areas less susceptible to the disease (buccal surface), with the aim of determining the possible roles of trace elements in the carious process. The samples were caries-free anterior incisors extracted for periodontal reasons from subjects 10-30 years of age. Prior to extraction of the sample teeth, a detailed dental history and examination was carried out in each individual. PIXE analysis, using a 3 MeV proton beam of 1 mm diameter, allowed the determination of Ca, Mn, Fe, Cu, Zn, Sr and Pb above detection limits. As demonstrated in this work, the enhanced sensitivity of PIXE analysis over electron microprobe analysis, and capability of localised surface analysis compared with the pooled samples require for neutron activation analysis, makes it a powerful and useful technique in dental analysis.

  10. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    Energy Technology Data Exchange (ETDEWEB)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured the trace gas emission factors from 7 prescribed fires in South Carolina, U.S. using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analyses. The fires were intended to emulate high-intensity burns as they were lit during the dry season and in most cases represented stands that had not been treated with prescribed burns in 10+ years, if at all. A total of 97 trace gas species are reported here from both airborne and ground-based platforms making this one of the most detailed field studies of fire emissions to date. The measurements included the first data for a suite of monoterpene compounds emitted via distillation of plant tissues during real fires. The known chemistry of the monoterpenes and their measured abundance of ~0.40% of CO (molar basis), ~3.9% of NMOC (molar basis), and ~21% of organic aerosol (mass basis), suggests that they impacted post-emission formation of ozone, aerosol, and small organic trace gases such as methanol and formaldehyde in the sampled plumes. The variability in the terpene emissions in South Carolina (SC) fire plumes was high and, in general, the speciation of the emitted gas-phase non-methane organic compounds was surprisingly different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that the slightly different ecosystems, time of year and the precursor variability all contributed to the variability in plume chemistry observed in this study and in the literature. The ΔHCN/ΔCO emission ratio, however, is fairly consistent at 0.9 ± 0.06 % for airborne fire measurements in coniferous-dominated ecosystems further confirming the value of HCN as a good biomass burning indicator/tracer. The SC results also support an earlier finding that C3-C4 alkynes may be of use as biomass burning indicators on the time-scale of

  11. Noble Gases

    Science.gov (United States)

    Podosek, F. A.

    2003-12-01

    The noble gases are the group of elements - helium, neon, argon, krypton, xenon - in the rightmost column of the periodic table of the elements, those which have "filled" outermost shells of electrons (two for helium, eight for the others). This configuration of electrons results in a neutral atom that has relatively low electron affinity and relatively high ionization energy. In consequence, in most natural circumstances these elements do not form chemical compounds, whence they are called "noble." Similarly, much more so than other elements in most circumstances, they partition strongly into a gas phase (as monatomic gas), so that they are called the "noble gases" (also, "inert gases"). (It should be noted, of course, that there is a sixth noble gas, radon, but all isotopes of radon are radioactive, with maximum half-life a few days, so that radon occurs in nature only because of recent production in the U-Th decay chains. The factors that govern the distribution of radon isotopes are thus quite different from those for the five gases cited. There are interesting stories about radon, but they are very different from those about the first five noble gases, and are thus outside the scope of this chapter.)In the nuclear fires in which the elements are forged, the creation and destruction of a given nuclear species depends on its nuclear properties, not on whether it will have a filled outermost shell when things cool off and nuclei begin to gather electrons. The numerology of nuclear physics is different from that of chemistry, so that in the cosmos at large there is nothing systematically special about the abundances of the noble gases as compared to other elements. We live in a very nonrepresentative part of the cosmos, however. As is discussed elsewhere in this volume, the outstanding generalization about the geo-/cosmochemistry of the terrestrial planets is that at some point thermodynamic conditions dictated phase separation of solids from gases, and that the

  12. [Characterization of severe acute occupational poisoning accidents related to irritating gases in China between 1989 and 2003].

    Science.gov (United States)

    Du, Xie-Yi; Zhang, Min; Wang, Huan-Qiang; Li, Tao; Wang, Hong-Fei; Chen, Shu-Yang; Zhang, Shuang; Qin, Jian; Ji, Li-Ying

    2006-12-01

    To analyze severe acute occupational poisoning accidents related to irritating gases reported in China between 1989 and 2003, and to study the characteristics of severe acute occupational poisoning accidents and provide scientific evidences for prevention and control strategies. The data from the national occupational poisoning case reporting system were analyzed with descriptive methods. (1) There were 92 severe acute occupational poisoning accidents related to asphyxiating gases during 15 years, which showed that there were 14.5 accidents occurred each year. Forty types of chemicals were reported to cause poisoning accidents directly. On average, there were 14.5 persons poisoned and 0.8 persons died of poisoning in each event. The number of death of poisoning reached 7 in most of the severe accidents. Chlorine was the main irritating gas resulting in poisoning accidents according to the number of accidents, cases and death. (1) The severe acute occupational poisoning related to irritating gases are more dangerous than others because of it is involved in more cases in each accident. (2) The accidents have concentricity in the certain types of chemicals, industries and jobs, and should be focused on control. (3) It is important to develop the program about early warning and forecast and the first aid.

  13. Greenhouse Gases

    Science.gov (United States)

    ... Production of Hydrogen Use of Hydrogen Greenhouse Gases Basics | | Did you know? Without naturally occurring greenhouse gases, the earth would be too cold to support life as we know it. Without the greenhouse effect, ...

  14. Decay of Iconic Memory Traces Is Related to Psychometric Intelligence: A Fixed-Links Modeling Approach

    Science.gov (United States)

    Miller, Robert; Rammsayer, Thomas H.; Schweizer, Karl; Troche, Stefan J.

    2010-01-01

    Several memory processes have been examined regarding their relation to psychometric intelligence with the exception of sensory memory. This study examined the relation between decay of iconic memory traces, measured with a partial-report task, and psychometric intelligence, assessed with the Berlin Intelligence Structure test, in 111…

  15. Trace-element geochemistry of coal resource development related to environmental quality and health

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This report assesses for decision makers and those involved in coal resource development the environmental and health impacts of trace-element effects arising from significant increases in the use of coal, unless unusual precautions are invoked. Increasing demands for energy and the pressing need for decreased dependence of the United States on imported oil require greater use of coal to meet the nation's energy needs during the next decade. If coal production and consumption are increased at a greatly accelerated rate, concern arises over the release, mobilization, transportation, distribution, and assimilation of certain trace elements, with possible adverse effects on the environment and human health. It is, therefore, important to understand their geochemical pathways from coal and rocks via air, water, and soil to plants, animals, and ultimately humans, and their relation to health and disease. To address this problem, the Panel on Trace Element Geochemistry of Coal Resource Development Related to Health (PECH) was established. Certain assumptions were made by the Panel to highlight the central issues of trace elements and health and to avoid unwarranted duplication of other studies. Based on the charge to the Panel and these assumptions, this report describes the amounts and distribution of trace elements related to the coal source; the various methods of coal extraction, preparation, transportation, and use; and the disposal or recycling of the remaining residues or wastes. The known or projected health effects are discussed at the end of each section.

  16. Remote sensing FTIR-system for emission monitoring and ambient air control of atmospheric trace gases and air pollutants; Remote sensing FTIR-System zur Emissions- und Immissionsmessung atmosphaerischer Spurengasse und Luftschadstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, T; Mosebach, H; Bittner, H [Kayser-Threde GmbH, Muenchen (Germany)

    1994-01-01

    The Fourier Transform Infrared spectrometer K300, based on the double-pendulum interferometer, is due to its optical design particularly suitable for high resolution remote sensing emission and transmission (long path monitoring) measurements of air pollutants and atmospheric trace gases in the field. The applications encompass direct emission measurements of hot flue gases and aircraft engine exhaust as well as surveillance of industrial complexes and waste disposal sites and ambient air control of e.g. traffic polluted sites. For direct emission measurements the infrared radiation of hot gases is utilized. Monitoring of cold diffuse emissions (e.g. at waste disposal sites) and ambient air control is carried out applying a bistatic transmission configuration with an artificial infrared source (glowbar) facing the instrument from a distance up to several hundred meters (long-path monitoring). Following a short introduction of the measurement technique and system, results from the above mentioned applications, obtained during several field studies are depicted and discussed. 19 refs., 8 figs., 12 tabs.

  17. Evaluation of Forensic DNA Traces When Propositions of Interest Relate to Activities

    DEFF Research Database (Denmark)

    Biedermann, Alex; Champod, Christophe; Jackson, Graham

    2016-01-01

    When forensic scientists evaluate and report on the probative strength of single DNA traces, they commonly rely on only one number, expressing the rarity of the DNA profile in the population of interest. This is so because the focus is on propositions regarding the source of the recovered trace...... demonstrated in day-to-day forensic practice and is also voiced in specialized literature. Yet many forensic scientists remain reluctant to assess their results given propositions that relate to different activities. Some scientists consider evaluations beyond the issue of source as being overly speculative...

  18. Event-related brain potential correlates of human auditory sensory memory-trace formation.

    Science.gov (United States)

    Haenschel, Corinna; Vernon, David J; Dwivedi, Prabuddh; Gruzelier, John H; Baldeweg, Torsten

    2005-11-09

    The event-related potential (ERP) component mismatch negativity (MMN) is a neural marker of human echoic memory. MMN is elicited by deviant sounds embedded in a stream of frequent standards, reflecting the deviation from an inferred memory trace of the standard stimulus. The strength of this memory trace is thought to be proportional to the number of repetitions of the standard tone, visible as the progressive enhancement of MMN with number of repetitions (MMN memory-trace effect). However, no direct ERP correlates of the formation of echoic memory traces are currently known. This study set out to investigate changes in ERPs to different numbers of repetitions of standards, delivered in a roving-stimulus paradigm in which the frequency of the standard stimulus changed randomly between stimulus trains. Normal healthy volunteers (n = 40) were engaged in two experimental conditions: during passive listening and while actively discriminating changes in tone frequency. As predicted, MMN increased with increasing number of standards. However, this MMN memory-trace effect was caused mainly by enhancement with stimulus repetition of a slow positive wave from 50 to 250 ms poststimulus in the standard ERP, which is termed here "repetition positivity" (RP). This RP was recorded from frontocentral electrodes when participants were passively listening to or actively discriminating changes in tone frequency. RP may represent a human ERP correlate of rapid and stimulus-specific adaptation, a candidate neuronal mechanism underlying sensory memory formation in the auditory cortex.

  19. The Pauli potential in relation to the differential virial theorem with application to experiments on ultracold atomic gases of fermions

    International Nuclear Information System (INIS)

    March, N.H.

    2008-08-01

    In early work by the writer introducing the Pauli potential VP (r) into density functional theory, the relation of VP (r) to the, as yet unknown, single-particle kinetic energy density functional was emphasized. Here, because of ongoing experiments on ultracold atomic gases of fermions, an explicit expression for the first derivative of VP (r) for an arbitrary number of closed shells generated by harmonic confinement is derived in terms of the spherically symmetric particle density n(r) and the confining potential. (author)

  20. Electronegative gases

    International Nuclear Information System (INIS)

    Christophorou, L.G.

    1981-01-01

    Recent knowledge on electronegative gases essential for the effective control of the number densities of free electrons in electrically stressed gases is highlighted. This knowledge aided the discovery of new gas dielectrics and the tailoring of gas dielectric mixtures. The role of electron attachment in the choice of unitary gas dielectrics or electronegative components in dielectric gas mixtures, and the role of electron scattering at low energies in the choice of buffer gases for such mixtures is outlined

  1. Field measurements of trace gases emitted by prescribed fires in southeastern US pine forests using an open-path FTIR system

    Science.gov (United States)

    S. K. Akagi; I. R. Burling; A. Mendoza; T. J. Johnson; M. Cameron; D. W. T. Griffith; C. Paton-Walsh; D. R. Weise; J. Reardon; R. J. Yokelson

    2013-01-01

    We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, US measured during the fall of 2011. The fires were more intense than many prescribed burns because the fuels included mature pine stands not subjected to prescribed fire in decades that were lit following an extended drought. The emission factors were measured...

  2. Green's functions and trace formulas for generalized Sturm-Liouville problems related by Darboux transformations

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2010-01-01

    We study Green's functions of the generalized Sturm-Liouville problems that are related to each other by Darboux -equivalently, supersymmetrical - transformations. We establish an explicit relation between the corresponding Green's functions and derive a simple formula for their trace. The class of equations considered here includes the conventional Schroedinger equation and generalizations, such as for position-dependent mass and with linearly energy-dependent potential, as well as the stationary Fokker-Planck equation.

  3. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    Science.gov (United States)

    Stockwell, Chelsea E.; Christian, Ted J.; Goetz, J. Douglas; Jayarathne, Thilina; Bhave, Prakash V.; Praveen, Puppala S.; Adhikari, Sagar; Maharjan, Rashmi; DeCarlo, Peter F.; Stone, Elizabeth A.; Saikawa, Eri; Blake, Donald R.; Simpson, Isobel J.; Yokelson, Robert J.; Panday, Arnico K.

    2016-09-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP) of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient) combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning), crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR) spectroscopy, whole-air sampling (WAS), and photoacoustic extinctiometers (PAX; 405 and 870 nm) based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs) for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg-1 fuel burned), single scattering albedos (SSAs), and absorption Ångström exponents (AAEs). From these data we estimate black and brown carbon (BC, BrC) emission factors (g kg-1 fuel burned). The trace gas measurements provide EFs (g kg-1) for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ˜ 80 gases in all). The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68) was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10). Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg-1), organic acids (7.66 ± 6.90 g kg-1), and HCN (2.01 ± 1.25 g kg-1), where the latter could

  4. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE: emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

    Directory of Open Access Journals (Sweden)

    C. E. Stockwell

    2016-09-01

    Full Text Available The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE campaign took place in and around the Kathmandu Valley and in the Indo-Gangetic Plain (IGP of southern Nepal during April 2015. The source characterization phase targeted numerous important but undersampled (and often inefficient combustion sources that are widespread in the developing world such as cooking with a variety of stoves and solid fuels, brick kilns, open burning of municipal solid waste (a.k.a. trash or garbage burning, crop residue burning, generators, irrigation pumps, and motorcycles. NAMaSTE produced the first, or rare, measurements of aerosol optical properties, aerosol mass, and detailed trace gas chemistry for the emissions from many of the sources. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared (FTIR spectroscopy, whole-air sampling (WAS, and photoacoustic extinctiometers (PAX; 405 and 870 nm based on field work with a moveable lab sampling authentic sources. The primary aerosol optical properties reported include emission factors (EFs for scattering and absorption coefficients (EF Bscat, EF Babs, in m2 kg−1 fuel burned, single scattering albedos (SSAs, and absorption Ångström exponents (AAEs. From these data we estimate black and brown carbon (BC, BrC emission factors (g kg−1 fuel burned. The trace gas measurements provide EFs (g kg−1 for CO2, CO, CH4, selected non-methane hydrocarbons up to C10, a large suite of oxygenated organic compounds, NH3, HCN, NOx, SO2, HCl, HF, etc. (up to ∼ 80 gases in all. The emissions varied significantly by source, and light absorption by both BrC and BC was important for many sources. The AAE for dung-fuel cooking fires (4.63 ± 0.68 was significantly higher than for wood-fuel cooking fires (3.01 ± 0.10. Dung-fuel cooking fires also emitted high levels of NH3 (3.00 ± 1.33 g kg−1, organic acids (7.66 ± 6.90 g kg−1, and HCN

  5. Zeta functions and regularized determinants related to the Selberg trace formula

    DEFF Research Database (Denmark)

    Momeni, Arash; Venkov, Alexei

    determinants of one dimensional Schroedinger operator for harmonic oscillator. We decompose the determinant of the automorphic Laplacian into a product of the determinants where each factor is a determinant representation of a zeta function related to Selberg's trace formula. Then we derive an identity...... connecting the determinants of the automorphic Laplacians on different Riemannian surfaces related to the arithmetical groups. Finally, by using the Jacquet-Langlands correspondence we connect the determinant of the automorphic Laplacian for the unit group of quaternions to the product of the determinants......For a general Fuchsian group of the first kind with an arbitrary unitary representation we define the zeta functions related to the contributions of the identity, hyperbolic, elliptic and parabolic conjugacy classes in Selberg's trace formula. We present Selberg's zeta function in terms...

  6. Greenhouse Gases

    Science.gov (United States)

    ... also produced by human activities. Some, such as industrial gases, are exclusively human made. What are the types ... Carbon dioxide (CO2) Methane (CH4) Nitrous oxide (N2O) Industrial gases: Hydrofluorocarbons (HFCs) Perfluorocarbons (PFCs) Sulfur hexafluoride (SF6 Nitrogen ...

  7. Influence of orographically induced transport process on the structure of the atmospheric boundary layer and on the distribution of trace gases; Einfluss orographisch induzierter Transportprozesse auf die Struktur der atmosphaerischen Grenzschicht und die Verteilung von Spurengasen

    Energy Technology Data Exchange (ETDEWEB)

    Kossmann, M.

    1998-04-01

    The influence of terrain on the structure of the atmospheric boundary-layer and the distribution of trace gases during periods of high atmospheric pressure was studied by means of meteorological and air-chemical data collected in September 1992 during the TRACT experiment in the transition area between the upper Rhine valley and the northern Black Forest. The emphasis was on the investigation of the development of the convective boundary layer, the formation of thermally induced circulation systems, and the orographic exchange between the atmospheric boundary layer and the free troposphere. Thanks to the extensive measurements, phenomena not yet described in literature could be verified by case studies, and processes that had only been established qualitatively could be quantified. (orig.)

  8. Event-related brain potentials reflect traces of echoic memory in humans.

    Science.gov (United States)

    Winkler, I; Reinikainen, K; Näätänen, R

    1993-04-01

    In sequences of identical auditory stimuli, infrequent deviant stimuli elicit an event-related brain potential component called mismatch negativity (MMN). MMN is presumed to reflect the existence of a memory trace of the frequent stimulus at the moment of presentation of the infrequent stimulus. This hypothesis was tested by applying the recognition-masking paradigm of cognitive psychology. In this paradigm, a masking sound presented shortly before or after a test stimulus diminishes the recognition memory of this stimulus, the more so the shorter the interval between the test and masking stimuli. This interval was varied in the present study. It was found that the MMN amplitude strongly correlated with the subject's ability to discriminate between frequent and infrequent stimuli. This result strongly suggests that MMN provides a measure for a trace of sensory memory, and further, that with MMN, this memory can be studied without performance-related distortions.

  9. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    Science.gov (United States)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    , SO2, C2-C4 alkanes, C2-C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b). Prominent in the second group, SO2 and NO were remarkably enhanced over the oil sands, with maximum mixing ratios of 38.7 ppbv and 5.0 ppbv, or 383× and 319× the local background, respectively. These SO2 levels are comparable to maximum values measured in heavily polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4, ethane and propane suggest low levels of natural gas leakage despite its heavy use at the surface mining sites. Instead the elevated CH4 levels are attributed to methanogenic tailings pond emissions. In addition to the emission of many trace gases, the natural drawdown of OCS by vegetation was absent above the surface mining operations, presumably because of the widespread land disturbance. Unexpectedly, the mixing ratios of α-pinene and β-pinene were much greater over the oil sands (up to 217 pptv and 610 pptv, respectively) than over vegetation in the background boundary layer (20±7 pptv and 84±24 pptv, respectively), and the pinenes correlated well with several industrial tracers that were elevated in the oil sands plumes. Because so few independent measurements from the oil sands mining industry exist, this study provides an important initial characterization of trace gas emissions from oil sands surface mining operations.

  10. Accelerated line-by-line calculations for the radiative transfer of trace gases related to climate studies

    International Nuclear Information System (INIS)

    Clough, S.A.

    1993-01-01

    In the present study we are studying the effects of including carbon dioxide, ozone, methane, and the halocarbons in addition to water vapor in the radiating atmosphere. The study has focused on two principal issues: the effect on the spectral fluxes and cooling rates of carbon dioxide, ozone and the halocarbons at 1990 concentration levels and the change in fluxes and cooling rates as a consequence of the anticipated ten year change in the profiles of these species. For the latter study the water vapor profiles have been taken as invariant in time. The radiative line-by-line calculations using LBLRTM (Line-By-Line Radiative Transfer Model) have been performed for tropical (TRP), mid-latitude winter (MLW) and mid-latitude summer (MLS) model atmospheres. The halocarbons considered in the present study are CCl 4 , CFC-11, CFC-12 and CFC-22. In addition to considering the radiative effects of carbon dioxide at 355 ppM, the assumed current level, we have also obtained results for doubled carbon dioxide at 710 ppM. An important focus of the current research effort is the effect of the ozone depletion profile on atmospheric radiative effects

  11. Process of radioactive waste gases

    International Nuclear Information System (INIS)

    Queiser, H.; Schwarz, H.; Schroter, H.J.

    1975-01-01

    A method is described in which the radiation level of waste gases from nuclear power plants containing both activation and fission gases is controlled at or below limits permitted by applicable standards by passing such gases, prior to release to the atmosphere, through an adsorptive delay path including a body of activated carbon having the relation to the throughput and character of such gases. (U.S.)

  12. Preserving objects, preserving memories: Repair professionals and object owners on the relation between traces on personal possessions and memories

    NARCIS (Netherlands)

    Zijlema, A.F.; van den Hoven, E.A.W.H.; Eggen, J.H.; Bakker, C.; Mugge, R.

    2017-01-01

    Traces of ageing and use on the material of products, and memories associated with products, have been found to contribute to product attachment and can stimulate product longevity. We present findings of a qualitative study that focused on the relation between traces of ageing and use on personal

  13. Activation analysis in a multitechnique study of trace element imbalances in age-related neurological diseases

    International Nuclear Information System (INIS)

    Ehmann, W.D.; Ding, X.X.; Khare, S.S.; Lovell, M.A.; Ni, B.F.; Tandon, L.; Vance, D.E.; Wenstrup, D.E.

    1993-01-01

    It has been suggested that several age-related neurological diseases such as Alzheimer's disease and amyotrophic lateral sclerosis may be related to environmental toxins. Bulk sample multielemental analyses by INAA alone are not adequate to define the role of trace elements in these diseases. A multitechnique approach has been developed that incorporates 14 MeV, instrumental reactor, radiochemical, and pre-irradiation chemical neutron activation analysis, together with laser microprobe mass spectrometry. The analytical scheme is able to provide bulk or protein normalized elemental concentrations, as well as microstructural, cellular, and subcellular localization information. (author) 21 refs.; 3 figs.; 3 tabs

  14. Trace metals in Antarctica related to climate change and increasing human impact.

    Science.gov (United States)

    Bargagli, R

    2000-01-01

    in most samples of atmospheric particulates, snow, ice, soils, and marine sediments from Antarctica can be taken as global background levels. Comparison between the results of trace element surveys in marine waters of the Southern Ocean and in other seas is practically impossible. The upwelling or subduction of water masses, the seasonality in ice cover and in phytoplankton biomass, the low fallout of atmospheric dust, and many other peculiar characteristics of the Southern Ocean make concentrations of trace metals in surface waters quite variable in space and time. The depletion of nutrients in surface waters, which is a regular feature of many marine environments, rarely occurs in the Southern Ocean. Waters in some regions are characterized by very low concentrations of Fe and Mn, whereas in others the content of Cd is relatively high at the beginning of summer and may decrease about one order of magnitude during the phytoplankton bloom. Although in most Antarctic coastal ecosystems the input of metals from geochemical and anthropogenic sources and from long-range transport is negligible, concentrations of Cd in the waters and biota may be higher than in waters and related species of organisms from polluted coastal areas. Like the Southern Ocean, Antarctic lakes have many peculiar characteristics. They are often perennially ice covered and without outlet, and their water, which is gained only from short-term melting of snow and glaciers in summer, is lost mainly by sublimation of surface ice. Several lakes are distinctly stratified: the water under the ice may be cool, rich in oxygen, and among the cleanest and clearest of natural waters, whereas water near the bottom becomes anoxic, tepid, and richer in major and trace elements. Considering the specificity of Antarctic environments, to evaluate the extent and consequences of global changes and increasing human activities in Antarctica itself, research on the biogeochemistry of trace metals and monitoring programs

  15. Can echoic memory store two traces simultaneously? A study of event-related brain potentials.

    Science.gov (United States)

    Winkler, I; Paavilainen, P; Näätänen, R

    1992-05-01

    The mismatch negativity, a component of the event-related brain potential elicited by infrequent deviants in sequences of auditory stimuli, is presumably generated by an automatic mismatch process in a mechanism that compares the current stimulus to the trace of the previous one. The present study addressed the possible simultaneous existence of two such traces. Two equiprobable (45% each) frequent stimuli ("standards"), one of 600 Hz and the other of 700 Hz, were presented together with an infrequent (10%), "deviant" stimulus which was of different frequency in different blocks. These deviants elicited a mismatch negativity, though a smaller one than that obtained in corresponding blocks with only one standard stimulus. Two aspects of the present results from the blocks with two standard stimuli implicate two parallel stimulus traces in these blocks: 1) deviants elicited a mismatch negativity (MMN) of approximately the same amplitude when preceded by sequences of four identical standards as when preceded by sequences of four stimuli containing both standards; 2) in contrast to the one-standard condition, the magnitude of stimulus deviance did not affect the MMN component elicited by the different deviants.

  16. Overview of the physical-chemical properties of the noble gases

    International Nuclear Information System (INIS)

    McKinley, C.

    1973-01-01

    This paper lists the concentrations of noble gases in the atmosphere and the relative abundance of the stable isotopes. Selected physical properties are tabulated; solubilities of noble gases in water and other liquids, and liquid-vapor equilibria data for binary systems containing a noble gas are presented. Adsorption data are tabulated for illustrative conventional adsorbents and are also presented by a Polanyi correlation. Clathration, biochemical effects, and chemical reactivity are highlighted. Analytical procedures are briefly described. Other relatively non-reactive gases present in the atmosphere in trace quantities are mentioned: methane, carbon tetrafluoride, and sulfur hexafluoride.

  17. Airborne measurements of reactive organic trace gases in the atmosphere - with a focus on PTR-MS measurements onboard NASA's flying laboratories

    Science.gov (United States)

    Wisthaler, Armin; Mikoviny, Tomas; Müller, Markus; Schiller, Sven Arne; Feil, Stefan; Hanel, Gernot; Jordan, Alfons; Mutschlechner, Paul; Crawford, James H.; Singh, Hanwant B.; Millet, Dylan

    2017-04-01

    Reactive organic gases (ROGs) play an important role in atmospheric chemistry as they affect the rates of ozone production, particle formation and growth, and oxidant consumption. Measurements of ROGs are analytically challenging because of their large variety and low concentrations in the Earth's atmosphere, and because they are easily affected by measurement artefacts. On aircraft, ROGs are typically measured by canister sampling followed by off-line analysis in the laboratory, fast online gas chromatography or online chemical ionization mass spectrometry. In this work, we will briefly sum up the state-of-the-art in this field before focusing on proton-transfer-reaction mass spectrometry (PTR-MS) and its deployment onboard NASA's airborne science laboratories. We will show how airborne PTR-MS was successfully used in NASA missions for characterizing emissions of ROGs from point sources, for following the photochemical evolution of ROGs in a biomass burning plume, for determining biosphere-atmosphere fluxes of selected ROGs and for validating satellite data. We will also present the airborne PTR-MS instrument in its most recent evolution which includes a radiofrequency ion funnel and ion guide combined with a compact time-of-flight mass spectrometer and discuss its superior performance characteristics. The development of the airborne PTR-MS instrument was supported by the Austrian Federal Ministry for Transport, Innovation and Technology (bmvit) through the Austrian Space Applications Programme (ASAP) of the Austrian Research Promotion Agency (FFG) (grants #833451, #847967). This work was also partly supported by NASA under grant #NNX14AP89G.

  18. Hydrodynamic modes, Green-Kubo relations, and velocity correlations in dilute granular gases

    International Nuclear Information System (INIS)

    Brey, J Javier; Ruiz-Montero, M J; Maynar, P; Garcia de Soria, M I

    2005-01-01

    It is shown that the hydrodynamic modes of a dilute granular gas of inelastic hard spheres can be identified, and calculated in the long wavelength limit. Assuming they dominate at long times, formal expressions for the Navier-Stokes transport coefficients are derived. They can be expressed in a form that generalizes the Green-Kubo relations for molecular systems, and it is shown that they can also be evaluated by means of N-particle simulation methods. The form of the hydrodynamic modes to zeroth order in the gradients is used to detect the presence of inherent velocity correlations in the homogeneous cooling state, even in the low density limit. They manifest themselves in the fluctuations of the total energy of the system. The theoretical predictions are shown to be in agreement with molecular dynamics simulations. Relevant related questions deserving further attention are pointed out

  19. MASERATI: a new rocket-borne diode laser absorption spectrometer for in-situ measurement of trace gases in the middle and upper atmosphere; MASERATI: Ein neues raketengetragenes Diodenlaser-Absorptionsspektrometer zur in situ-Messung von Spurengasen in der mittleren und oberen Atmosphaere

    Energy Technology Data Exchange (ETDEWEB)

    Lucke, H. von

    1999-09-01

    MASERATI (middle atmosphere spectrometric experiment on Rockets for the analysis of trace gas influences) is the first rocket-borne tunable diode laser absorption spectrometer (TDLAS). It was developed to measure water vapor and carbon dioxide in the altitude range from 50 to 90 km and 120 km, respectively. Infrared absorption spectroscopy using two laser diodes is applied to measure both trace gases simultaneously. The laser beams are sent into an open multiple-pass absorption setup mounted on top of the sounding rocket. High sensitivity is achieved by means of frequency modulation and lock-in techniques. The results of several tests performed in the laboratory demonstrate that the instrument is capable of detecting relative absorbances down to 10{sup -4} - 10{sup -5} when integrating spectra for 1 s. Two almost identical MASERATI instruments have been built and launched on sounding rockets from the Andoeya rocket range (69 N, 16 E) in northern Norway during winter 1997/98. The results of these flights demonstrate that MASERATI is a new suitable tool for in situ studies of the mesosphere and lower thermosphere. (orig.)

  20. A Portable FTIR Analyser for Field Measurements of Trace Gases and their Isotopologues: CO2, CH4, N2O, CO, del13C in CO2 and delD in water vapour

    Science.gov (United States)

    Griffith, D. W.; Bryant, G. R.; Deutscher, N. M.; Wilson, S. R.; Kettlewell, G.; Riggenbach, M.

    2007-12-01

    We describe a portable Fourier Transform InfraRed (FTIR) analyser capable of simultaneous high precision analysis of CO2, CH4, N2O and CO in air, as well as δ13C in CO2 and δD in water vapour. The instrument is based on a commercial 1 cm-1 resolution FTIR spectrometer fitted with a mid-IR globar source, 26 m multipass White cell and thermoelectrically-cooled MCT detector operating between 2000 and 7500 cm-1. Air is passed through the cell and analysed in real time without any pre-treatment except for (optional) drying. An inlet selection manifold allows automated sequential analysis of samples from one or more inlet lines, with typical measurement times of 1-10 minutes per sample. The spectrometer, inlet sampling sequence, real-time quantitative spectrum analysis, data logging and display are all under the control of a single program running on a laptop PC, and can be left unattended for continuous measurements over periods of weeks to months. Selected spectral regions of typically 100-200 cm-1 width are analysed by a least squares fitting technique to retrieve concentrations of trace gases, 13CO2 and HDO. Typical precision is better than 0.1% without the need for calibration gases. Accuracy is similar if measurements are referenced to calibration standard gases. δ13C precision is typically around 0.1‰, and for δD it is 1‰. Applications of the analyser include clean and polluted air monitoring, tower-based flux measurements such as flux gradient or integrated horizontal flux measurements, automated soil chambers, and field-based measurements of isotopic fractionation in soil-plant-atmosphere systems. The simultaneous multi-component advantages can be exploited in tracer-type emission measurements, for example of CH4 from livestock using a co-released tracer gas and downwind measurement. We have also developed an open path variant especially suited to tracer release studies and measurements of NH3 emissions from agricultural sources. An illustrative

  1. A new laboratory facility to study the interactions of aerosols, cloud droplets/ice crystals, and trace gases in a turbulent environment: The Π Chamber

    Science.gov (United States)

    Cantrell, W. H., II; Chang, K.; Ciochetto, D.; Niedermeier, D.; Bench, J.; Shaw, R. A.

    2014-12-01

    A detailed understanding of gas-aerosol-cloud interaction within the turbulent atmosphere is of prime importance for an accurate understanding of Earth's climate system. As one example: While every cloud droplet began as an aerosol particle, not every aerosol particle becomes a cloud droplet. The particle to droplet transformation requires that the particle be exposed to some critical concentration of water vapor, which differs for different combinations of particle size and chemical composition. Similarly, the formation of ice particles in mixed phase clouds is also catalyzed by aerosol particles. Even in the simplest scenarios it is challenging to gain a full understanding of the aerosol activation and ice nucleation processes. At least two other factors contribute significantly to the complexity observed in the atmosphere. First, aerosols and cloud particles are not static entities, but are continuously interacting with their chemical environment, and therefore changing in their properties. Second, clouds are ubiquitously turbulent, so thermodynamic and compositional variables, such as water vapor or other trace gas concentrations, fluctuate in space and time. Indeed, the coupling between turbulence and microphysical processes is one of the major research challenges in cloud physics. We have developed a multiphase, turbulent reaction chamber, (dubbed the Π Chamber, after the internal volume of 3.14 cubic meters) designed to address the problems outlined above. It is capable of pressures ranging from sea level to ~ 100 mbar, and can sustain temperatures of +40 to -55 ºC. We can independently control the temperatures on the surfaces of three heat transfer zones. This allows us to establish a temperature gradient between the floor and ceiling inducing Rayleigh-Benard convection and inducing a turbulent environment. Interior surfaces are electropolished stainless steel to facilitate cleaning before and after chemistry experiments. At present, supporting

  2. Irritant gases

    NARCIS (Netherlands)

    Meulenbelt, J

    Acute inhalation injury can result from the use of household cleaning agents (e.g. chlorine, ammonia), industrial or combustion gases (e.g. sulfur dioxide, nitrogen oxides) or bioterrorism. The severity of the injury is to a great extent determined by the circumstances of exposure. If exposure was

  3. The research of electrical tracing system construction management and related questions of BOP project

    International Nuclear Information System (INIS)

    Wang Lining; Li Jingmin; Ma Ding; Tu Haitao

    2015-01-01

    Based on Hongyanhe nuclear power plant in Liaoning province, the paper studies the anti-freeze and heat tracing work of BOP project. It compares several different heat tracing solutions in terms of technicality and applicability, and gave the most suitable scheme by using electrical tracing. It also presents the construction details of the electrical tracing system, analyzes the key points of the construction management from quantity, safety and schedule aspects, and gave the improvement suggestions. (authors)

  4. Related research with thermo hydraulics safety by means of Trace code; Investigaciones relacionadas con seguridad termohidraulica con el codigo TRACE

    Energy Technology Data Exchange (ETDEWEB)

    Chaparro V, F. J.; Del Valle G, E. [IPN, Escuela Superior de Fisica y Matematicas, UP - Adolfo Lopez Mateos, Edif. 9, 07738 Mexico D. F. (Mexico); Rodriguez H, A.; Gomez T, A. M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Sanchez E, V. H.; Jager, W., E-mail: evalle@esfm.ipn.mx [Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz I, D-76344 Eggenstein - Leopoldshafen (Germany)

    2014-10-15

    In this article the results of the design of a pressure vessel of a BWR/5 similar to the type of Laguna Verde NPP are presented, using the Trace code. A thermo hydraulics Vessel component capable of simulating the behavior of fluids and heat transfer that occurs within the reactor vessel was created. The Vessel component consists of a three-dimensional cylinder divided into 19 axial sections, 4 azimuthal sections and two concentric radial rings. The inner ring is used to contain the core and the central part of the reactor, while the outer ring is used as a down comer. Axial an azimuthal divisions were made with the intention that the dimensions of the internal components, heights and orientation of the external connections match the reference values of a reactor BWR/5 type. In the model internal components as, fuel assemblies, steam separators, jet pumps, guide tubes, etc. are included and main external connections as, steam lines, feed-water or penetrations of the recirculation system. The model presents significant simplifications because the object is to keep symmetry between each azimuthal section of the vessel. In most internal components lack a detailed description of the geometry and initial values of temperature, pressure, fluid velocity, etc. given that it only considered the most representative data, however with these simulations are obtained acceptable results in important parameters such as the total flow through the core, the pressure in the vessel, percentage of vacuums fraction, pressure drop in the core and the steam separators. (Author)

  5. Experimental Research of Influence of a Relative Particles Positioning in a Gas Stream on Characteristics of their Aerodynamic Traces

    Directory of Open Access Journals (Sweden)

    Volkov Roman S.

    2016-01-01

    Full Text Available The cycle of experimental studies on determination of length of aerodynamic traces of the particles which are flowed round by an air stream is executed. When carrying out researches, panoramic optical methods for diagnostics of multiphase flows of PIV and PTV were used. Velocities of an air flow were varied in the range of 1-3 m/s. The sizes of particles changed from 1mm to 5 mm. The defining influence of the sizes of particles and velocities of an air stream on length of aerodynamic traces is established. Influence of a relative positioning of particles on features of formation of an aerodynamic trace is shown.

  6. Industrial gases

    International Nuclear Information System (INIS)

    Hunter, D.; Jackson, D.; Coeyman, M.

    1993-01-01

    Industrial gas companies have fought hard to boost sales and hold margins in the tough economic climate, and investments are well down from their 1989-'91 peak. But 'our industry is still very strong long term' says Alain Joly, CEO of industry leader L'Air Liquide (AL). By 1994, if a European and Japanese recovery follows through on one in the U.S., 'we could see major [investment] commitments starting again,' he says. 'Noncryogenic production technology is lowering the cost of gas-making possible new applications, oxygen is getting plenty of attention in the environmental area, and hydrogen also fits into the environmental thrust,' says Bob Lovett, executive v.p./gases and equipment with Air Products ampersand Chemicals (AP). Through the 1990's, 'Industrial gases could grow even faster than in the past decade,' he says. Virtually a new generation of new gases applications should become reality by the mid-1990s, says John Campbell, of industry consultants J.R. Campbell ampersand Associates (Lexington, MA). Big new oxygen volumes will be required for powder coal injection in blast furnaces-boosting a steel mill's requirement as much as 40% and coal gasification/combined cycle (CGCC). Increased oil refinery hydroprocessing needs promise hydrogen requirements

  7. Greenhouse gases reduction potential through consumer’s behavioral changes in terms of food-related product selection

    International Nuclear Information System (INIS)

    Yoshikawa, Naoki; Fujiwara, Natsumi; Nagata, Junko; Amano, Koji

    2016-01-01

    Highlights: • Greenhouse gases (GHG) reduction potential by shopping behavior change is analyzed. • Four scenarios related to food consumption is evaluated using life cycle assessment. • Total GHG reduction potential by four scenarios in Japan is 1367 kt-CO_2/year. • Potential reduces to 45% when considering feasible ratio of taking behavior change. • Contribution of seasonal production/consumption scenario is highest among scenarios. - Abstract: Sustainable consumption plays an important role in the mitigation of global warming and the conservation of energy. Promoting more environmentally responsible consumer behavior, especially through open communication between stakeholders, is one way to achieve low-carbon consumption. This study evaluates the potential for reducing greenhouse gas (GHG) emissions through behavioral transformation of consumers in terms of their daily shopping habits. In this context, the behavioral transformative actions pertain to certain foods and daily necessities, and are analyzed from a life cycle assessment perspective. We developed multiple product-selection scenarios to evaluate GHG emissions related to the daily purchase of commodities. Based on the life cycle assessment, we estimated the GHG emissions that result from the production and distribution of these commodities, pertaining to both the current product selection and to a possibly improved selection. The results of our study show that because of seasonal consumption patterns and energy conversion, there is a substantial potential to reduce GHG emissions resulting from out-of-season produce cultivation. The GHG reduction potential is not high for each individual commodity because diverse commodities are needed on a daily basis. However, various actions in combination could have substantial potential for reducing emissions.

  8. Concentrations of trace elements in human tissues and relation of ratios of mutual metals to the human health

    International Nuclear Information System (INIS)

    Ling-wei, X.; Shao-xian, L.; Xiao-juan, Z.

    1989-01-01

    According to the experimental results, the concentrations and concentrations in order, of trace elements in human tissues among Changsha's People in China are reported. The authors particularly present that the ratios of mutual metals (M/N) in normal physiological tissues and fluids are very important factors which indicate the metabolic situations of trace elements in the body and as the indices which evaluate the situation of human health. (M and N mean the concentrations of different trace elements in the tissues or fluids, respectively.) Up to now, it is still an interesting field to study the functions of trace elements for the human health. There are previously some reports about the concentrations of trace elements in normal physiological tissues/ or organs and fluids of human body. These provide very valuable data for biological medicine. In the study presented atomic absorption method was adopted in order to determine the concentrations of Zn, Cu, Mn, Ni, Pb and Cd in human tissues (liver, spleen, kidney, bone, lung, pancreas, heart and artery and muscle) at autopsy. The authors suggest that trace elements, are contained in the body in an aproportional way, in normal physiological tissues and fluids, and the ratios may directly indicate metabolic situation of trace elements in the body which further reveal the mystery of trace elements for human health. Therefore, the ratios M/N as an indicator of health is more proper than that only using concentrations of trace elements. Schroeder (1973) reported that incidence of heart disease is related to the imbalance of ration Zn/Cd and Zn/Cu rather than the concentrations of Zn, Cd, Cu, and the intellectual development also depends on the proper proportion among copper, cadmium, lead, zinc in the body

  9. Development of an integrated energy concept: survey of the potential for reducing emissions of climate-influencing trace gases through efficient utilisation in the old Laender. Sector traffic

    International Nuclear Information System (INIS)

    Oppermann, F.

    1993-11-01

    If CO 2 emissions are to be reduced on account of their major contribution to the anthropogenic greenhouse effect, as planned, for example, by the Federal Government, then a key role will have to be assigned to the traffic sector because this is the only sector whose energy consumption and consequent CO 2 emissions is relentlessly increasing. This forms the background to the present study's intent of sketching out possible routes of development of the traffic system in the old Laender. Three scenarios having particular regard to traffic-related CO 2 emissions are presented. The study is based on the reference years 1987, 2005, and 2020; its scope is defined by the so-called inland concept. The scenario calculations are based on, firstly, a detailed quantitative survey of the West German traffic system in 1987 as the starting year and, secondly, a dp-supported traffic model that is capable of generating a scenario and describes traffic systems in terms of parameters such as traffic volume and CO 2 emissions taking interdependencies with other energy consuming sectors into account. Working from a general transsectoral scenario formulation, measures appropriate to the respective framework conditions governing the three scenarios 'Business as usual' (BAU), 'Efficiency', and 'Ecologically structured policy' are defined and the resulting effects on the individual elements of the traffic system are assessed. The results of the subsequently performed scenario calculations largely consist of detailed, absolute, traffic-volume-specific CO 2 emission values for each reference year. (orig.) [de

  10. Five-year measurements of ambient ammonia and its relationships with other trace gases at an urban site of Delhi, India

    Science.gov (United States)

    Saraswati; Sharma, S. K.; Mandal, T. K.

    2018-04-01

    In this study, we present the 5-year measurements of ambient ammonia (NH3), oxides of nitrogen (NO and NO2) and carbon monoxide (CO) along with the meteorological parameters at an urban site of Delhi, India from January 2011 to December 2015. The average mixing ratios of ambient NH3, NO, NO2 and CO over the entire period of observations were recorded as 19.3 ± 4.4 (ppb), 20.1 ± 5.9 (ppb), 18.6 ± 4.6 (ppb) and 1.8 ± 0.5 (ppm), respectively. The mixing ratios of NH3, NO, NO2 and CO were recorded highest during winter season, followed by summer and monsoon season. In the present case, a substantial seasonal variation of NH3 was observed during all the seasons except NO, NO2 and CO. The results emphasized that the traffic could be one of the significant sources of ambient NH3 at the urban site of Delhi as illustrated by positive correlations of NH3 with traffic related pollutants (NO x and CO). Surface wind as well as back trajectory analysis also supports the road side traffic and agricultural activities at the nearby area indicating possible major sources of ambient NH3 at observational site. Trajectory analysis, potential source contribution function and concentration weighted trajectory analysis indicated the surrounding nearby areas (NCR, Haryana, Punjab, Rajasthan and Uttar Pradesh) as a significant source region of ambient NH3 at the observational site of Delhi.

  11. PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk

    International Nuclear Information System (INIS)

    Saha, Priyanka; Sen Raychaudhuri, Sarmistha; Chakraborty, Anindita; Sudarshan, Mathummal

    2010-01-01

    Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.

  12. Chemistry, transport and dry deposition of trace gases in the boundary layer over the tropical Atlantic Ocean and the Guyanas during the GABRIEL field campaign

    Directory of Open Access Journals (Sweden)

    A. Stickler

    2007-07-01

    Full Text Available We present a comparison of different Lagrangian and chemical box model calculations with measurement data obtained during the GABRIEL campaign over the tropical Atlantic Ocean and the Amazon rainforest in the Guyanas, October 2005. Lagrangian modelling of boundary layer (BL air constrained by measurements is used to derive a horizontal gradient (≈5.6 pmol/mol km−1 of CO from the ocean to the rainforest (east to west. This is significantly smaller than that derived from the measurements (16–48 pmol/mol km−1, indicating that photochemical production from organic precursors alone cannot explain the observed strong gradient. It appears that HCHO is overestimated by the Lagrangian and chemical box models, which include dry deposition but not exchange with the free troposphere (FT. The relatively short lifetime of HCHO implies substantial BL-FT exchange. The mixing-in of FT air affected by African and South American biomass burning at an estimated rate of 0.12 h−1 increases the CO and decreases the HCHO mixing ratios, improving agreement with measurements. A mean deposition velocity of 1.35 cm/s for H2O2 over the ocean as well as over the rainforest is deduced assuming BL-FT exchange adequate to the results for CO. The measured increase of the organic peroxides from the ocean to the rainforest (≈0.66 nmol/mol d−1 is significantly overestimated by the Lagrangian model, even when using high values for the deposition velocity and the entrainment rate. Our results point at either heterogeneous loss of organic peroxides and/or their radical precursors, underestimated photodissociation or missing reaction paths of peroxy radicals not forming peroxides in isoprene chemistry. We calculate a mean integrated daytime net ozone production (NOP in the BL of (0.2±5.9 nmol/mol (ocean and (2.4±2.1 nmol/mol (rainforest. The NOP strongly correlates with NO and has a positive tendency in

  13. Determination of trace elements in wool fibre by instrumental neutron activation analysis and relation between trace element contents and quality of wool

    International Nuclear Information System (INIS)

    Eozyol, H.

    1990-01-01

    Wool samples were analyzed by neutron activation analysis and 17 elements, Al, Ag, Au, As, Br, Ca, Co, Cr, Cu, Fe, La, Mg, Mn, Na, Sb, Se and Zn were measured quantitatively. The presence of seven others, Ce, Eu, I, Mo, Te and W was noted. Since several elements, such as Cd, Hg and Pb could not be conveniently determined by NAA, Atomic Absorption Spectroscopy (AAS) was used instead. Cu and Zn were also analyzed by NAA and AAS to compare these two methods. Mechanical properties of samples were measured and the relations between the trace element contents and properties were investigated. (author) 16 refs.; 7 tabs

  14. Chromatography related performance of the Monitor for Aerosols and Gases in Ambient Air (MARGA): laboratory and field based evaluation

    Science.gov (United States)

    Evaluation of the semi-continuous Monitor for Aerosols and Gases in Ambient Air (MARGA, Metrohm Applikon B.V.) was conducted with an emphasis on examination of accuracy and precision associated with processing of chromatograms. Using laboratory standards and atmospheric measureme...

  15. Service Delivery and Related Issues at the Trace Research and Development Center.

    Science.gov (United States)

    Smith, R. O.

    The environmental context of the Trace Center is first briefly described as background for a more detailed description of the center's service delivery activities in the field of rehabilitation/education technology. Trace serves four major functions in rehabilitation/education technology. As a nationally funded rehabilitation engineering center,…

  16. Survey of reference materials. V. 2: Environmentally related reference materials for trace elements, nuclides and microcontaminants

    International Nuclear Information System (INIS)

    1996-05-01

    The present report presently contains over 250 reference materials with trace element and organic contaminant information on fuel, geological and mineral, anthropogenic disposal, soil reference and miscellaneous reference materials. Not included in the current report is information on most biological and environmental reference materials with trace element, stable isotope, radioisotope and organic contaminant information. 8 refs, tabs

  17. Traffic-related trace elements in soils along six highway segments on the Tibetan Plateau: Influence factors and spatial variation.

    Science.gov (United States)

    Wang, Guanxing; Zeng, Chen; Zhang, Fan; Zhang, Yili; Scott, Christopher A; Yan, Xuedong

    2017-03-01

    The accumulation of traffic-related trace elements in soil as the result of anthropogenic activities raises serious concerns about environmental pollution and public health. Traffic is the main source of trace elements in roadside soil on the Tibetan Plateau, an area otherwise devoid of industrial emissions. Indeed, the rapid development of tourism and transportation in this region means it is becoming increasingly important to identify the accumulation levels, influence distance, spatial distribution, and other relevant factors influencing trace elements. In this study, 229 soil samples along six segments of the major transportation routes on the Tibetan Plateau (highways G214, S308, and G109), were collected for analysis of eight trace elements (Cr, Co, Ni, As, Cu, Zn, Cd, and Pb). The results of statistical analyses showed that of the eight trace elements in soils, Cu, Zn, Cd, and Pb were primarily derived from traffic. The relationship between the trace element accumulation levels and the distance from the roadside followed an exponential decline, with the exception of Segment 3, the only unpaved gravel road studied. In addition, the distance of influence from the roadside varied by trace element and segment, ranging from 16m to 144m. Background values for each segment were different because of soil heterogeneity, while a number of other potential influencing factors (including traffic volume, road surface material, roadside distance, land cover, terrain, and altitude) all had significant effects on trace-element concentrations. Overall, however, concentrations along most of the road segments investigated were at, or below, levels defined as low on the Nemero Synthesis index. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Trace Formulae of Characteristic Polynomial and Cayley-Hamilton's Theorem, and Applications to Chiral Perturbation Theory and General Relativity

    International Nuclear Information System (INIS)

    Zhang Honghao; Yan Wenbin; Li Xuesong

    2008-01-01

    By using combinatorics, we give a new proof for the recurrence relations of the characteristic polynomial coefficients, and we further obtain an explicit expression for the generic term of the coefficient sequence, which yields the trace formulae of the Cayley-Hamilton's theorem with all coefficients explicitly given. This implies a byproduct, a complete expression for the determinant of any finite-dimensional matrix in terms of the traces of its successive powers. And we discuss some of their applications to chiral perturbation theory and general relativity

  19. The use of nuclear related analytical techniques for the determination of ingestion and body content of trace elements

    International Nuclear Information System (INIS)

    Djojosubroto, H.; Santoso, D.; Widjajakusuma, B.

    1998-01-01

    A number of observations revealed that various human disease states are associated with measurable abnormalities of trace element levels. Until present there is no data on trace element levels in human tissues and dietary intake representing the population in Indonesia. Trace element level in various biological materials, especially human serum related to health syndrome (e.g. acute myocardial infarction and goiter prevalences) was performed by National Atomic Energy Agency in cooperation with relevant institutes. The present study is concerned with determination of ingestion and organ content of trace elements of importance in radiological protection (Cs, Sr, I, Th and U). Quantitation of the elements in the samples will be determined by neutron activation analysis, complemented by nuclear related analytical techniques, e.g. inductively coupled plasma - mass spectrometry and atomic absorption spectrometry. Samples to be analyzed consist of (a) total diets and individual staple foodstuffs, (b) autopsy specimens of liver, lung, kidney, muscle, thyroid and bone, and (c) drinking water. It seems difficult for us to define nationally representative specimens of total diets and individual staple foodstuffs. Based on these facts, in the first year activity samples of dietary intake from various socio economic levels of population in West Java will be collected. Human tissue sample is obtained from autopsy of normal persons who are killed in traffic accident or homicide victim. Traces of Th and U in drinking water are determined by neutron activation analysis following preconcentration of these elements in chelating resin Chlelex 100. (author)

  20. Fuel gases

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    This paper gives a brief presentation of the context, perspectives of production, specificities, and the conditions required for the development of NGV (Natural Gas for Vehicle) and LPG-f (Liquefied Petroleum Gas fuel) alternative fuels. After an historical presentation of 80 years of LPG evolution in vehicle fuels, a first part describes the economical and environmental advantages of gaseous alternative fuels (cleaner combustion, longer engines life, reduced noise pollution, greater natural gas reserves, lower political-economical petroleum dependence..). The second part gives a comparative cost and environmental evaluation between the available alternative fuels: bio-fuels, electric power and fuel gases, taking into account the processes and constraints involved in the production of these fuels. (J.S.)

  1. Trace Elements in Dominant Species of the Fenghe River, China: Their Relations to Environmental Factors.

    Science.gov (United States)

    Yang, Yang; Zhou, Zhengchao; Bai, Yanying; Jiao, Wentao; Chen, Weiping

    2016-07-01

    The distribution of trace elements (TEs) in water, sediment, riparian soil and dominant plants was investigated in the Fenghe River, Northwestern China. The Fenghe River ecosystem was polluted with Cd, Cr, Hg and Pb. There was a high pollution risk in the midstream and downstream regions and the risk level for Cd was much higher than that of the other elements. The average values of bioconcentration coefficient for Cd and Zn were 2.21 and 1.75, respectively, indicating a large accumulation of Cd and Zn in the studied species. With broad ecological amplitudes, L. Levl. et Vant. Trin., and L. had the greatest TE concentrations in aboveground and belowground biomass of the studied species and were potential biomonitors or phytoremediators for the study area. Multivariate techniques including cluster analysis, correlation analysis, principal component analysis, and canonical correspondence analysis were used to analyze the relations between TE concentrations in plants and various environmental factors. The soil element concentration is the main factor determining the accumulation of TEs in plants. The co-release behavior of common pollutants and TEs drove the accumulation of Hg, Cd, and As in the studied plants. Significant enrichment of some elements in the Fenghe River has led to a decline in the biodiversity of plants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Do event-related potentials to infrequent decrements in duration of auditory stimuli demonstrate a memory trace in man?

    Science.gov (United States)

    Näätänen, R; Paavilainen, P; Reinikainen, K

    1989-12-15

    Sequences of identical acoustic stimuli were presented to normal subjects reading a book while event-related brain potentials (ERP) elicited by these stimuli were recorded. Occasional irrelevant decreases and increases in stimulus duration elicited an ERP component called the mismatch negativity (MMN). This component was larger over the right hemisphere irrespective of the ear stimulated. These data implicate memory representations which develop automatically and represent the physical features of the repetitive stimulus accurately. Further, when an input does not match with such a trace the MMN is generated. The memory traces involved appear to be those of the acoustic sensory memory, the 'echoic' memory.

  3. Iterative maximum a posteriori (IMAP-DOAS for retrieval of strongly absorbing trace gases: Model studies for CH4 and CO2 retrieval from near infrared spectra of SCIAMACHY onboard ENVISAT

    Directory of Open Access Journals (Sweden)

    C. Frankenberg

    2005-01-01

    Full Text Available In the past, differential optical absorption spectroscopy (DOAS has mostly been employed for atmospheric trace gas retrieval in the UV/Vis spectral region. New spectrometers such as SCIAMACHY onboard ENVISAT also provide near infrared channels and thus allow for the detection of greenhouse gases like CH4, CO2, or N2O. However, modifications of the classical DOAS algorithm are necessary to account for the idiosyncrasies of this spectral region, i.e. the temperature and pressure dependence of the high resolution absorption lines. Furthermore, understanding the sensitivity of the measurement of these high resolution, strong absorption lines by means of a non-ideal device, i.e. having finite spectral resolution, is of special importance. This applies not only in the NIR, but can also prove to be an issue for the UV/Vis spectral region. This paper presents a modified iterative maximum a posteriori-DOAS (IMAP-DOAS algorithm based on optimal estimation theory introduced to the remote sensing community by rodgers76. This method directly iterates the vertical column densities of the absorbers of interest until the modeled total optical density fits the measurement. Although the discussion in this paper lays emphasis on satellite retrieval, the basic principles of the algorithm also hold for arbitrary measurement geometries. This new approach is applied to modeled spectra based on a comprehensive set of atmospheric temperature and pressure profiles. This analysis reveals that the sensitivity of measurement strongly depends on the prevailing pressure-height. The IMAP-DOAS algorithm properly accounts for the sensitivity of measurement on pressure due to pressure broadening of the absorption lines. Thus, biases in the retrieved vertical columns that would arise in classical algorithms, are obviated. Here, we analyse and quantify these systematic biases as well as errors due to variations in the temperature and pressure profiles, which is indispensable for

  4. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  5. A report on the trace element investigations in relation to cardio-vascular diseases

    International Nuclear Information System (INIS)

    Cruz, B. de la; Lansangan, L.M.; Paradero, R.R.; Asprer, G.

    1976-03-01

    Zinc, copper and molybdenum has both beneficial and harmful effects to the health of an individual. It has been found that zinc has a protective action against hypertension, while copper maintains the elasticity of the blood vessels, and at the same time, an increase in copper can also enhance atherogenesis. In this investigation, amounts of the said trace elements have been determined in ten normal male subjects who met accidental death. The normal values obtained in these subjects were compared to the mean values of their trace elements obtained from patients who died of ischaemic heart diseases

  6. An integrative solution for managing, tracing and citing sensor-related information

    Science.gov (United States)

    Koppe, Roland; Gerchow, Peter; Macario, Ana; Schewe, Ingo; Rehmcke, Steven; Düde, Tobias

    2017-04-01

    In a data-driven scientific world, the need to capture information on sensors used in the data acquisition process has become increasingly important. Following the recommendations of the Open Geospatial Consortium (OGC), we started by adopting the SensorML standard for describing platforms, devices and sensors. However, it soon became obvious to us that understanding, implementing and filling such standards costs significant effort and cannot be expected from every scientist individually. So we developed a web-based sensor management solution (https://sensor.awi.de) for describing platforms, devices and sensors as hierarchy of systems which supports tracing changes to a system whereas hiding complexity. Each platform contains devices where each device can have sensors associated with specific identifiers, contacts, events, related online resources (e.g. manufacturer factsheets, calibration documentation, data processing documentation), sensor output parameters and geo-location. In order to better understand and address real world requirements, we have closely interacted with field-going scientists in the context of the key national infrastructure project "FRontiers in Arctic marine Monitoring ocean observatory" (FRAM) during the software development. We learned that not only the lineage of observations is crucial for scientists but also alert services using value ranges, flexible output formats and information on data providers (e.g. FTP sources) for example. Mostly important, persistent and citable versions of sensor descriptions are required for traceability and reproducibility allowing seamless integration with existing information systems, e.g. PANGAEA. Within the context of the EU-funded Ocean Data Interoperability Platform project (ODIP II) and in cooperation with 52north we are proving near real-time data via Sensor Observation Services (SOS) along with sensor descriptions based on our sensor management solution. ODIP II also aims to develop a harmonized

  7. Application of the FTIR system K300 for the emission and immission measurement of atmospheric trace gases and harmful substances in the air: examples of cases and results. Anwendung des FTIR-Systems K300 zur Emissions- und Immissionsmessung atmosphaerischer Spurengase und Luftschadstoffe: Fallbeispiele und Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, T [Kayser-Threde GmbH, Muenchen (Germany); Mosebach, H [Kayser-Threde GmbH, Muenchen (Germany); Bittner, H [Kayser-Threde GmbH, Muenchen (Germany)

    1993-01-01

    The K300 double oscillation interferometer used for the investigations is a Fourier transform infrared (FTIR) spectrometer which, due to its special optical design, is very suitable for high resolution remote sensing emission and immission (long-path monitoring) measurements of harmful substances in the air and atmospheric trace gases, when used in the field. The spectrum of applications extends from the direct measurement of hot chimney waste gases and of engine exhaust gases via the monitoring of industrial plants or waste dumps (diffuse emission) to the immission measurement of sites with heavy traffic. For direct emission measurements, the infrared characteristic radiation of hot waste gases is used; for the measurement of cold diffuse emission or immission, one measures against an artificial infrared source of radiation, which can be erected at a distance of several hundred metres from the equipment (bistatic configuration, socalled long-path monitoring). The results of different applications, which were obtained in the context of various campaigns of measurements, are shown after a short introduction of the system. (orig./BBR)

  8. Validation and application of the system code TRACE for safety related investigations of innovative nuclear energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Wadim

    2011-12-19

    The system code TRACE is the latest development of the U.S. Nuclear Regulatory Commission (US NRC). TRACE, developed for the analysis of operational conditions, transients and accidents of light water reactors (LWR), is a best-estimate code with two fluid, six equation models for mass, energy, and momentum conservation, and related closure models. Since TRACE is mainly applied to LWR specific issues, the validation process related to innovative nuclear systems (liquid metal cooled systems, systems operated with supercritical water, etc.) is very limited, almost not existing. In this work, essential contribution to the validation of TRACE related to lead and lead alloy cooled systems as well as systems operated with supercritical water is provided in a consistent and corporate way. In a first step, model discrepancies of the TRACE source code were removed. This inconsistencies caused the wrong prediction of the thermo physical properties of supercritical water and lead bismuth eutectic, and hence the incorrect prediction of heat transfer relevant characteristic numbers like Reynolds or Prandtl number. In addition to the correction of the models to predict these quantities, models describing the thermo physical properties of lead and Diphyl THT (synthetic heat transfer medium) were implemented. Several experiments and numerical benchmarks were used to validate the modified TRACE version. These experiments, mainly focused on wall-to-fluid heat transfer, revealed that not only the thermo physical properties are afflicted with inconsistencies but also the heat transfer models. The models for the heat transfer to liquid metals were enhanced in a way that the code can now distinguish between pipe and bundle flow by using the right correlation. The heat transfer to supercritical water was not existing in TRACE up to now. Completely new routines were implemented to overcome that issue. The comparison of the calculations to the experiments showed, on one hand, the necessity

  9. The evolution of minor active and toxic gases in repositories

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.; Davies, A.A.; McGahan, D.J.; Rushbrook, P.E.

    1988-09-01

    This study has considered a number of toxic and active gases which could potentially form in relatively small amounts in a deep repository for radioactive wastes. It has been concluded that many of these would react under repository conditions or be highly soluble in groundwater. The minor amounts of the inert and relatively insoluble gas krypton-85 would dissolve in a small volume of repository water. The wide range of organic gases and vapours that could form in trace amounts has been shortened to a list of 21 by consideration of their toxicity, volatibility and extent of formation at a landfill site for non-radioactive waste. The amounts of the inert and inactive gas helium formed from α-particles and the decay of tritium will have only a very minor effect on the overall rate of gas production. (author)

  10. Contact tracing with a real-time location system: A case study of increasing relative effectiveness in an emergency department.

    Science.gov (United States)

    Hellmich, Thomas R; Clements, Casey M; El-Sherif, Nibras; Pasupathy, Kalyan S; Nestler, David M; Boggust, Andy; Ernste, Vickie K; Marisamy, Gomathi; Koenig, Kyle R; Hallbeck, M Susan

    2017-12-01

    Contact tracing is the systematic method of identifying individuals potentially exposed to infectious diseases. Electronic medical record (EMR) use for contact tracing is time-consuming and may miss exposed individuals. Real-time location systems (RTLSs) may improve contact identification. Therefore, the relative effectiveness of these 2 contact tracing methodologies were evaluated. During a pertussis outbreak in the United States, a retrospective case study was conducted between June 14 and August 31, 2016, to identify the contacts of confirmed pertussis cases, using EMR and RTLS data in the emergency department of a tertiary care medical center. Descriptive statistics and a paired t test (α = 0.05) were performed to compare contacts identified by EMR versus RTLS, as was correlation between pertussis patient length of stay and the number of potential contacts. Nine cases of pertussis presented to the emergency department during the identified time period. RTLS doubled the potential exposure list (P < .01). Length of stay had significant positive correlation with contacts identified by RTLS (ρ = 0.79; P = .01) but not with EMR (ρ = 0.43; P = .25). RTLS doubled the potential pertussis exposures beyond EMR-based contact identification. Thus, RTLS may be a valuable addition to the practice of contact tracing and infectious disease monitoring. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  11. On the trace-free Einstein equations as a viable alternative to general relativity

    International Nuclear Information System (INIS)

    Ellis, George F R; Van Elst, Henk; Murugan, Jeff; Uzan, Jean-Philippe

    2011-01-01

    The quantum field theoretical prediction for the vacuum energy density leads to a value for the effective cosmological constant that is incorrect by between 60 and 120 orders of magnitude. We review an old proposal of replacing Einstein's field equations by their trace-free part (the trace-free Einstein equations), together with an independent assumption of energy-momentum conservation by matter fields. While this does not solve the fundamental issue of why the cosmological constant has the value that is observed cosmologically, it is indeed a viable theory that resolves the problem of the discrepancy between the vacuum energy density and the observed value of the cosmological constant. However, one has to check that, as well as preserving the standard cosmological equations, this does not destroy other predictions, such as the junction conditions that underlie the use of standard stellar models. We confirm that no problems arise here: hence, the trace-free Einstein equations are indeed viable for cosmological and astrophysical applications. (papers)

  12. Active moss biomonitoring of trace elements with Sphagnum girgensohnii moss bags in relation to atmospheric bulk deposition in Belgrade, Serbia

    International Nuclear Information System (INIS)

    Anicic, M.; Tasic, M.; Frontasyeva, M.V.; Tomasevic, M.; Rajsic, S.; Mijic, Z.; Popovic, A.

    2009-01-01

    Active biomonitoring with wet and dry moss bags was used to examine trace element atmospheric deposition in the urban area of Belgrade. The element accumulation capability of Sphagnum girgensohnii Russow was tested in relation to atmospheric bulk deposition. Moss bags were mounted for five 3-month periods (July 2005-October 2006) at three representative urban sites. For the same period monthly bulk atmospheric deposition samples were collected. The concentrations of Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb were determined by instrumental neutron activation analyses and atomic absorption spectrometry. Significant accumulation of most elements occurred in the exposed moss bags compared with the initial moss content. High correlations between the elements in moss and bulk deposits were found for V, Cu, As, and Ni. The enrichment factors of the elements for both types of monitor followed the same pattern at the corresponding sites. - Accumulated trace elements in the moss Sphagnum girgensohnii reflect atmospheric deposition

  13. Trace Analysis of Boron in Nuclear Graphite by Means of Gas Chromatography; Analyse de traces de bore dans le graphite nucleaire au moyen de la chromatographie gazeuse; Analiz metodom gazovoj khromatografii sledov bora v yadernom grafite; Analisis de vestigios de boro en el grafito nuclear por cromatografia de gases

    Energy Technology Data Exchange (ETDEWEB)

    Zado, F. [Rudjer Boskovlc Institute, Zagreb, Yugoslavia (Croatia)

    1963-11-15

    No literature is available about the application of gas chromatography in trace analysis of boron in graphite. The following methods of transformation of boron into its volatile compounds are discussed: (a) Ignition of graphite in a stream of oxygen and subsequent transformation of boron oxide into volatile methyl borate which is then analysed on a Dilkens Aerograph H Model 96 gas chromatograph with silicone column and hydrogen as carrier (concentration method). (b) Extraction of boron from the graphite by means of sodium fluoride at 2800{sup o}C with simultaneous chlorination and trapping of boron trichloride, which is then analysed (direct method). A home-made gas chromatograph with a thermal conductivity detector and nitrogen as a carrier was used. The column was made of glass with a 20% (wt./wt.) fluorocarbon oil on kieselguhr. Special precautions were taken on account of the sensitivity of boron trichloride to moisture. (author) [French] Rien n'a ete publie sur l'application de la chromatographie gazeuse a l'analyse de traces de bore dans le graphite. L'auteur examine les methodes suivantes de transformation du bore en composes volatils: a) Brulage du graphite dans un courant d'oxygene, puis transformation de l'oxyde de bore en borate de methyle volatil, que l'on analyse ensuite a l'aide d'un appareil a chromatographie gazeuse Dilkens Aerograph H, Modele 96, utilisant une colonne de silicium et de rhydrogene comme entrafheur (methode de concentration). b) Extraction du bore contenu dans le graphite par chauffage avec du fluorure de sodium a 2800{sup o}C, avec chloruration simultanee et captage du trichlorure de bore qui est ensuite analyse (methode directe). On s' est servi d'un appareil a chromatographie gazeuse construit sur place, dote d'un detecteur a conductibilite thermique et utilisant l'azote comme entrafheur. La colonne etait faite de verre contenant 20% en poids de fluorocarbure huileux sur du kieselguhr. Des precautions particulieres ont ete prises

  14. Rare gases in Samoan xenoliths

    Science.gov (United States)

    Poreda, R. J.; Farley, K. A.

    1992-09-01

    The rare gas isotopic compositions of residual harzburgite xenoliths from Savai'i (SAV locality) and an unnamed seamount south of the Samoan chain (PPT locality) provide important constraints on the rare gas evolution of the mantle and atmosphere. Despite heterogeneous trace element compositions, the rare gas characteristics of the xenoliths from each of the two localities are strikingly similar. SAV and PPT xenoliths have 3He/ 4He ratios of11.1 ± 0.5 R A and21.6 ± 1 R A, respectively; this range is comparable to the 3He/ 4He ratios in Samoan lavas and clearly demonstrates that they have trapped gases from a relatively undegassed reservoir. The neon results are not consistent with mixing between MORB and a plume source with an atmospheric signature. Rather, the neon isotopes reflect either a variably degassed mantle (with a relative order of degassing of Loihi Honda et al. that the 20Ne/ 22Ne ratio in the mantle more closely resembles the solar ratio than the atmospheric one. 40Ar/ 36Ar ratios in the least contaminated samples range from 4,000 to 12,000 with the highest values in the 22 RA PPT xenoliths. There is no evidence for atmospheric 40Ar/ 36Ar ratios in the mantle source of these samples, which indicates that the lower mantle may have 40Ar/ 36Ar ratios in excess of 5,000. Xenon isotopic anomalies in 129Xe and 136Xe are as high as 6%, or about half of the maximum MORB excess and are consistent with the less degassed nature of the Samoan mantle source. These results contradict previous suggestions that the high 3He/ 4He mantle has a near-atmospheric heavy rare gas isotopic composition.

  15. Trace gas emissions from burning Florida wetlands

    Science.gov (United States)

    Cofer, Wesley R.; Levine, Joel S.; Winstead, Edward L.; Lebel, Peter J.; Koller, Albert M.; Hinkle, C. Ross

    1990-02-01

    Measurements of biomass burn-produced trace gases are presented that were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide (CO2) normalized emission ratios (ΔX/ΔCO2; V/V; where X is trace gas) for carbon monoxide (CO), hydrogen (H2), methane (CH4), total nonmethane hydrocarbons (TNMHC), and nitrous oxide (N2O) were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncus roemerianus. Some interspersed scrub oak (Quercus spp) and saw palmetto (Screnoa repens) were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. We believe that the consistently low emission ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes (both small-size fuels) burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly diminished.

  16. Trace element concentrations in freshwater mussels and macrophytes as related to those in their environment

    Directory of Open Access Journals (Sweden)

    Gian Maria BEONE

    2003-02-01

    Full Text Available This study was primarily designed to contribute to the debate "Do accumulator species reflect the element contamination level of their environment?" This research was carried out: 1 to know the distribution of 15 trace elements and calcium in shell and soft tissues of three species of freshwater mussels and macrophytes; 2 to compare the accumulation capacity of each trace element by mussels and by eight species of macrophytes and 3 to test the relationships between the metal concentrations in the mussels and macrophytes and those in water and sediments. The variability of element residues in the mussels is the major limit to accumulator monitoring. The most important causes are: seasonal cycle, physical environment and biological factors such as the size, age and growth rate. This research was designed to eliminate the consequence of variability deriving from the season and the environment. To this end the mussels and macrophytes were collected at the same time from the same habitat: Ranco Bay, Lago Maggiore, Northern Italy. In addition, the element concentrations in more size-classes of the most abundant mussel species (Unio pictorum and Dreissena polymorpha were measured. Trace elements were analyzed by Inductive Coupled Plasma-Mass Spectrometry (ICP-MS. By arranging the data in sequences of decreasing element concentrations in the organisms as well as in water and sediments, we were able to compare the accumulating ability of the tested species and evaluate their capacity to reflect environmental availability. Neither the sequences in the shell nor those in the tissues were similar to the sequence in the water. The differences between the sequences of the mussel tissues and those of the sediments were less striking than those between shells and sediments. Similar results were obtained by macrophytes. In conclusion, the results of this study (which mimics the monitoring practice prove that bioaccumulators cannot be used to evaluate the

  17. Microbial production and consumption of greenhouse gases: methane, nitrogen oxides, and halomethanes

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.E.; Whitman, W.B.

    1991-01-01

    The aim is to provide an overview of the biological processes that contribute to the increase in trace gases (CH[sub 4], N[sub 2]O, NO[sub x] and halocarbons) in the atmosphere. Physical and chemical processes are discussed as they relate to biological processes. It is an introduction to biological processes that contribute to changes in global climate and processes that can be influenced by biofeedback mechanisms as climate changes occur.

  18. Greenhouse gases and global warming

    International Nuclear Information System (INIS)

    1995-01-01

    From previous articles we have learned about the complexities of our environment, its atmosphere and its climate system. we have also learned that climate change and, therefore global warm and cool periods are naturally occurring phenomena. Moreover, all scientific evidence suggests that global warming, are likely to occur again naturally in the future. However, we have not yet considered the role of the rates of climate change in affecting the biosphere. It appears that how quickly the climate changes may be more important than the change itself. In light of this concern, let us now consider the possibility that, is due to human activity. We may over the next century experience global warming at rates and magnitudes unparalleled in recent geologic history. The following questions are answered; What can we learn from past climates? What do we know about global climates over the past 100 years? What causes temperature change? What are the greenhouse gases? How much have concentration of greenhouse gases increased in recent years? Why are increases in concentrations of greenhouse of concern? What is the e nhanced greenhouse effect ? How can human activity impact the global climate? What are some reasons for increased concentrations of greenhouse gases? What are fossil fuel and how do they transform into greenhouse gases? Who are the biggest emitters of greenhouse gases? Why are canada per capita emissions of greenhouse gases relatively high? (Author)

  19. EQUATION OF STATE IN FORM WHICH RELATES MOL FRACTION AND MOLARITY OF TWO (OR MORE COMPONENT THERMODYNAMIC SYSTEM CONSISTED OF IDEAL GASES, AND IT'S APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Marko Popović

    2010-01-01

    Full Text Available Most people would face a problem if there is a need to calculate the mole fraction of a substance A in a gaseous solution (a thermodynamic system containing two or more ideal gases knowing its molarity at a given temperature and pressure. For most it would take a lot of time and calculations to find the answer, especially because the quantities of other substances in the system aren't given. An even greater problem arises when we try to understand how special relativity affects gaseous systems, especially solutions and systems in equilibrium. In this paper formulas are suggested that greatly shorten the process of conversion from molarity to mole fraction and give us a better insight into the relativistic effects on a gaseous system.

  20. Macrobenthic community in the Douro estuary: relations with trace metals and natural sediment characteristics

    International Nuclear Information System (INIS)

    Mucha, A.P.; Vasconcelos, M.T.S.D.; Bordalo, A.A.

    2003-01-01

    This study used a novel approach to detect a clear signature of metal contamination and biological impacts in an estuary. - The relationship between macrobenthic community structure and natural characteristics of sediment and trace metal contamination were studied in the lower Douro estuary (Portugal, NW, Iberian Peninsula), using an innovative threefold approach (SQG, Sediment Quality Guidelines), metal normalization to Fe, and macrobenthic community structure. This study allowed detection of a clear signature of anthropogenic contamination, in terms of Zn, Cu, Pb, and Cr in the north bank of the estuary, which experiences high urban pressure. Using the SQG approach, metal concentrations above ERM (effects range--median) were observed only at one sampling station, but several stations had levels above ERL (effects range-low). The macrobenthic community had a low diversity, with only 19 species found in the entire estuarine area, dominated by opportunistic species. The granulometric distribution of the sediments (estimated from the combination of organic matter, Fe and Al) seemed to be the major structuring factor for the communities, establishing the natural macrobenthic distribution pattern. The metals (Zn, Cu, Pb, and Cr) seemed to act as a disturbing factor over the natural distribution, with deleterious consequences for the macrobenthic communities

  1. Related research with thermo hydraulics safety by means of Trace code

    International Nuclear Information System (INIS)

    Chaparro V, F. J.; Del Valle G, E.; Rodriguez H, A.; Gomez T, A. M.; Sanchez E, V. H.; Jager, W.

    2014-10-01

    In this article the results of the design of a pressure vessel of a BWR/5 similar to the type of Laguna Verde NPP are presented, using the Trace code. A thermo hydraulics Vessel component capable of simulating the behavior of fluids and heat transfer that occurs within the reactor vessel was created. The Vessel component consists of a three-dimensional cylinder divided into 19 axial sections, 4 azimuthal sections and two concentric radial rings. The inner ring is used to contain the core and the central part of the reactor, while the outer ring is used as a down comer. Axial an azimuthal divisions were made with the intention that the dimensions of the internal components, heights and orientation of the external connections match the reference values of a reactor BWR/5 type. In the model internal components as, fuel assemblies, steam separators, jet pumps, guide tubes, etc. are included and main external connections as, steam lines, feed-water or penetrations of the recirculation system. The model presents significant simplifications because the object is to keep symmetry between each azimuthal section of the vessel. In most internal components lack a detailed description of the geometry and initial values of temperature, pressure, fluid velocity, etc. given that it only considered the most representative data, however with these simulations are obtained acceptable results in important parameters such as the total flow through the core, the pressure in the vessel, percentage of vacuums fraction, pressure drop in the core and the steam separators. (Author)

  2. Evaluation of Forensic DNA Traces When Propositions of Interest Relate to Activities: Analysis and Discussion of Recurrent Concerns

    Science.gov (United States)

    Biedermann, Alex; Champod, Christophe; Jackson, Graham; Gill, Peter; Taylor, Duncan; Butler, John; Morling, Niels; Hicks, Tacha; Vuille, Joelle; Taroni, Franco

    2016-01-01

    When forensic scientists evaluate and report on the probative strength of single DNA traces, they commonly rely on only one number, expressing the rarity of the DNA profile in the population of interest. This is so because the focus is on propositions regarding the source of the recovered trace material, such as “the person of interest is the source of the crime stain.” In particular, when the alternative proposition is “an unknown person is the source of the crime stain,” one is directed to think about the rarity of the profile. However, in the era of DNA profiling technology capable of producing results from small quantities of trace material (i.e., non-visible staining) that is subject to easy and ubiquitous modes of transfer, the issue of source is becoming less central, to the point that it is often not contested. There is now a shift from the question “whose DNA is this?” to the question “how did it get there?” As a consequence, recipients of expert information are now very much in need of assistance with the evaluation of the meaning and probative strength of DNA profiling results when the competing propositions of interest refer to different activities. This need is widely demonstrated in day-to-day forensic practice and is also voiced in specialized literature. Yet many forensic scientists remain reluctant to assess their results given propositions that relate to different activities. Some scientists consider evaluations beyond the issue of source as being overly speculative, because of the lack of relevant data and knowledge regarding phenomena and mechanisms of transfer, persistence and background of DNA. Similarly, encouragements to deal with these activity issues, expressed in a recently released European guideline on evaluative reporting (Willis et al., 2015), which highlights the need for rethinking current practice, are sometimes viewed skeptically or are not considered feasible. In this discussion paper, we select and discuss

  3. Measurements of 4 Atmospheric Trace Gases Outside Homes Adjacent to a Multiwell Pad During Drilling, Hydraulic Fracturing, and Production Phases, Using Low-Cost Sensors and Artificial Neural Network Quantification Techniques

    Science.gov (United States)

    Casey, J. G.; Ilie, A. M. C.; Coffey, E.; Collier-Oxandale, A. M.; Hannigan, M.; Vaccaro, C.

    2017-12-01

    In Colorado and elsewhere in North America, the oil and gas production industry has been growing alongside and in the midst of increasing urban and rural populations. These coinciding trends have resulted in a growing number of people living in close proximity to petroleum production and processing activities, leading to potential public health impacts. Combustion-related emissions from heavy-duty diesel vehicle traffic, generators, compressors, and production stream flaring can potentially lead to locally enhanced levels of nitrogen oxides (NOx), carbon monoxide (CO), and carbon dioxide (CO2). Venting and fugitive emissions of production stream constituents can potentially lead to locally enhanced levels of methane (CH4) and volatile organic compounds (VOCs), some of which (like benzene) are known carcinogens. NOx and VOC emissions can also potentially increase local ozone (O3) production. After learning of a large new multiwell pad on the outskirts of Greeley, Colorado, we were able to quickly mobilize portable air quality monitors outfitted with low-cost gas sensors that respond to CH4, CO2, CO, and O3. The air quality monitors were installed outside homes adjacent to the new multiwell pad several weeks prior to the first spud date. An anemometer was also installed outside one of the homes in order to monitor wind speed and direction. Measurements continued during drilling, hydraulic fracturing, and production phases. The sensors were periodically collocated with reference instruments at a nearby regulatory air quality monitoring site towards calibration via field normalization and validation. Artificial Neural Networks were employed to map sensor signals to trace gas mole fractions during collocation periods. We present measurements of CH4, CO2, CO, and O3 in context with wellpad activities and local meteorology. CO and O3 observations are presented in context with regional measurements and National Ambient Air Quality Standards for each. Wind speed and

  4. Measurements of relative subshell photoionization cross-sections in several solids and nobel gases, by x-ray and UV photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Kemeny, P.C.

    1974-01-01

    Subshell photoionization cross-sections of both core and valence electrons in solid samples of sodium fluoride and sodium chloride were measured at a photon energy of 1487 eV (Al Kα). Relative to the sodium 1s level, values are reported for the subshell photoionization cross-sections of the sodium 2s, 2p, chlorine 2s, 2p, 3s, 3p and fluorine 1s, 2s and 2p levels. Subshell photoionization cross-sections of outer levels in the noble gases neon through xenon were also measured, at photon energies of 21.22, 40.81 and 48.37 eV. Values are reported for the photoionization cross-sections of the neon 2p, krypton 4p, xenon 5p and xenon 5s levels, relative to that of the argon 3p level. Whereever possible, comparison was made between the present relative subshell photoionization cross-section values and those reported by other workers. (author)

  5. Semantics of trace relations in requirements models for consistency checking and inferencing

    NARCIS (Netherlands)

    Göknil, Arda; Ivanov, Ivan; van den Berg, Klaas; Veldhuis, Jan-Willem

    2009-01-01

    Requirements traceability is the ability to relate requirements back to stakeholders and forward to corresponding design artifacts, code, and test cases. Although considerable research has been devoted to relating requirements in both forward and backward directions, less attention has been paid to

  6. [Gases in vitreoretinal surgery].

    Science.gov (United States)

    Janco, L; Vida, R; Bartos, M; Villémová, K; Izák, M

    2012-02-01

    To evaluate the importance and benefits of using gases in vitreoretinal surgery. The gases represent a wide group of substances used in eye surgery for more than 100 years. The role of intraocular gases in vitreoretinal surgery is irreplaceable. Their use is still considered to be the "gold standard". An important step in eye surgery was the introduction of expanding gases--sulfur hexafluoride and perfluorocarbons into routine clinical practice. The most common indications for the use of intraocular gases are: retinal detachment, idiopathic macular hole, complications of vitreoretinal surgery and others. The introduction of intraocular gases into routine clinical practice, along with other modern surgical techniques resulted in significant improvement of postoperative outcomes in a wide range of eye diseases. Understanding the principles of intraocular gases use brings the benefits to the patient and physician as well. Due to their physical and chemical properties they pose far the best and most appropriate variant of intraocular tamponade. Gases also bring some disadvantages, such as difficulties in detailed fundus examination, visual acuity testing, ultrasonographic examination, difficulties in application of intravitreal drugs or reduced possibility of retina laser treatment. The gases significantly change optical system properties of the eye. The use of gases in vitreoretinal surgery has significantly increased success rate of retinal detachment surgery, complicated posterior segment cases, trauma, surgery of the macula and other diseases.

  7. Effects of Low-Carbon Technologies and End-Use Electrification on Energy-Related Greenhouse Gases Mitigation in China by 2050

    Directory of Open Access Journals (Sweden)

    Zheng Guo

    2015-07-01

    Full Text Available Greenhouse gas emissions in China have been increasing in line with its energy consumption and economic growth. Major means for energy-related greenhouse gases mitigation in the foreseeable future are transition to less carbon intensive energy supplies and structural changes in energy consumption. In this paper, a bottom-up model is built to examine typical projected scenarios for energy supply and demand, with which trends of energy-related carbon dioxide emissions by 2050 can be analyzed. Results show that low-carbon technologies remain essential contributors to reducing emissions and altering emissions trends up to 2050. By pushing the limit of current practicality, emissions reduction can reach 20 to 28 percent and the advent of carbon peaking could shift from 2040 to 2030. In addition, the effect of electrification at end-use sectors is studied. Results show that electrifying transport could reduce emissions and bring the advent of carbon peaking forward, but the effect is less significant compared with low-carbon technologies. Moreover, it implies the importance of decarbonizing power supply before electrifying end-use sectors.

  8. Biomonitoring of air pollution in Jamaica through trace-element analysis of epiphytic plants using nuclear and related analytical techniques

    International Nuclear Information System (INIS)

    Vutchkov, Mitko

    2001-01-01

    The main goal of the Coordinated Research Project (No:9937/R0), entitled 'Biomonitoring of Air Pollution in Jamaica Through Trace-Element Analysis of Epiphytic Plants Using Nuclear and Related Analytical Techniques', is to identify and validate site specific epiphytic plants for biomonitoring the atmospheric pollution in Jamaica using nuclear analytical techniques at the International Centre for Environmental and Nuclear Sciences (ICENS). The specific objectives for the second year of the project were: Development of HOP for sampling epiphytic plants in Jamaica; Sampling design and sample collection; Sample preparation and analysis; Development of an in-house SRM and participation in the NAT-5 inter-laboratory study; Data analysis and interpretation of the results; Development of a work plan of the third year of the project

  9. Tracing Clues

    DEFF Research Database (Denmark)

    Feldt, Liv Egholm

    The past is all messiness and blurred relations. However, we tend to sort the messiness out through rigorous analytical studies leaving the messiness behind. Carlo Ginzburgs´ article Clues. Roots of an Evidential Paradigm from 1986 invigorates methodological elements of (historical) research, which...... central methodological elements will be further elaborated and discussed through a historical case study that traces how networks of philanthropic concepts and practices influenced the Danish welfare state in the period from the Danish constitution of 1849 until today. The overall aim of this paper...

  10. Economic efficiency assessment of greenhouse gases mitigation for agriculture; Analyse af omkostningseffektiviteten ved drivhusgasreducerende tiltag i relation til landbruget

    Energy Technology Data Exchange (ETDEWEB)

    Dubgaard, A.; Moeller Laugesen, F.; Staehl, E.E.; Bang, J.R.; Schou, E.; Jacobsen, Brian H.; Oerum, J.E.; Dejgaerd Jensen, J.

    2013-08-15

    The report contains the contributions by the Institute of Food and Resource Economics (IFRO) to a Danish Government appraisal of greenhouse gas (GHG) reduction measures. The policy goal is a 40 per cent reduction in total Danish GHG emissions by 2020 compared to 1990. The GHGs analysed in the present study include emissions of CO{sub 2}, nitrous oxide and methane plus soil carbon sequestration. The purpose of the study is to identify GHG mitigation measures related to agriculture which can deliver cost-effective contributions to the targeted reduction in GHG emissions in Denmark. A total of 21 GHG mitigation measures are included in the assessment. The stipulated implementation period is 2013 to 2020. The cost calculations have a time horizon equal to 30 years, i.e. from 2013 to 2042. The GHG reduction potential, expressed in CO{sub 2} equivalents (CO{sub 2}-eq), is calculated as the sum of the effect on the emission of CO{sub 2} (with and without changes in soil carbon), methane and nitrous oxide. The 21 mitigation measures are listed below (figures in brackets show the assumed implementation potential): 1. Biogas from livestock manure/slurry (10 % of total slurry production) 2. Biogas from slurry and maize (10 % of total slurry production) 3. Biogas from organic clover 4. Additional fat in diet for dairy cows (80% of conventional dairy cow stock and 20 % of organic dairy cow stock) 5. Additional concentrated feed in diet for other cattle (25 % of cattle stock under 2 years of age) 6. Prolonged lactation period for dairy cows (10 % of dairy cow stock) 7. Acidification of slurry (10 % of total slurry production) 8. Covers on slurry containers (40 % of total slurry production) 9. Cooling of pig slurry (10 % of pig slurry) 10. Nitrification inhibitors in nitrate fertilisers (100 % of chemical fertilisers with nitrogen) 11. Increased nitrogen utilization requirement for degassed slurry in nitrogen quota system (50 % of total slurry production) 12. Increased nitrogen

  11. Children's Performance on Pseudoword Repetition Depends on Auditory Trace Quality: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Ceponiene, Rita; Service, Elisabet; Kurjenluoma, Sanna; Cheour, Marie; Naatanen, Risto

    1999-01-01

    Compared the mismatch-negativity (MMN) component of auditory event-related brain potentials to explore the relationship between phonological short-term memory and auditory-sensory processing in 7- to 9-year olds scoring the highest and lowest on a pseudoword repetition test. Found that high and low repeaters differed in MMN amplitude to speech…

  12. The impact of lifestyle factors on age-related differences in hair trace element content in pregnant women in the third trimester.

    Science.gov (United States)

    Skalny, Anatoly V; Tinkov, Alexey A; Voronina, Irina; Terekhina, Olga; Skalnaya, Margarita G; Bohan, Tatiana G; Agarkova, Lyubov A; Kovas, Yulia

    2018-01-01

    Trace elements play a significant role in the regulation of human reproduction, while advanced age may have a significant impact on trace element metabolism. The objective of the present study was to assess the impact of lifestyle factors on age-related differences in hair trace element content in pregnant women in the third trimester. A total of 124 pregnant women aged 20–29 (n = 72) and 30–39 (n = 52) were ex- amined. Scalp hair trace element content was assessed using inductively coupled plasma mass spectrometry at NexION 300D (Perkin Elmer, USA) after microwave digestion. The results showed that the elder pregnant women had 36% (p = 0.009), 14% (p = 0.045), and 45% (p = 0.044) lower hair Zn, V, and Cd content, and 16% (p = 0.044) higher hair B levels – in comparison to the respective younger group values. Multiple regression analysis demonstrated that the age of the women had a significant influence on hair V and Zn levels. B content was also significantly influenced by age at first intercourse, smoking status, and specific dietary habits. None of the lifestyle factors were associated with hair Cd content in pregnant women. Hair V levels were also affected by following a special diet. Interestingly, alcohol intake did not have a significant impact on hair trace element content. These data indicate that lifestyle factors have a significant influence on age-related changes in hair trace elements during pregnancy that may impact the outcome of pregnancy.

  13. Extraction with supercritical gases

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, G M; Wilke, G; Stahl, E

    1980-01-01

    The contents of this book derives from a symposium on the 5th and 6th of June 1978 in the ''Haus der Technik'' in Essen. Contributions were made to separation with supercritical gases, fluid extraction of hops, spices and tobacco, physicochemical principles of extraction, phase equilibria and critical curves of binary ammonia-hydrocarbon mixtures, a quick method for the microanalytical evaluation of the dissolving power of supercritical gases, chromatography with supercritical fluids, the separation of nonvolatile substances by means of compressed gases in countercurrent processes, large-scale industrial plant for extraction with supercritical gases, development and design of plant for high-pressure extraction of natural products.

  14. Handbook of purified gases

    CERN Document Server

    Schoen, Helmut

    2015-01-01

    Technical gases are used in almost every field of industry, science and medicine and also as a means of control by government authorities and institutions and are regarded as indispensable means of assistance. In this complete handbook of purified gases the physical foundations of purified gases and mixtures as well as their manufacturing, purification, analysis, storage, handling and transport are presented in a comprehensive way. This important reference work is accompanied with a large number of Data Sheets dedicated to the most important purified gases.  

  15. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  16. TRACING THE STAR-FORMATION-DENSITY RELATION TO z {approx} 2

    Energy Technology Data Exchange (ETDEWEB)

    Quadri, Ryan F.; Williams, Rik J. [Carnegie Observatories, Pasadena, CA 91101 (United States); Franx, Marijn; Hildebrandt, Hendrik, E-mail: quadri@obs.carnegiescience.edu [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands)

    2012-01-10

    Recent work has shown that the star formation (SF) density relation-in which galaxies with low SF rates are preferentially found in dense environments-is still in place at z {approx} 1, but the situation becomes less clear at higher redshifts. We use mass-selected samples drawn from the UKIDSS Ultra-Deep Survey to show that galaxies with quenched SF tend to reside in dense environments out to at least z {approx} 1.8. Over most of this redshift range we are able to demonstrate that this SF-density relation holds even at fixed stellar mass. The environmental quenching of SF appears to operate with similar efficiency on all galaxies regardless of stellar mass. Nevertheless, the environment plays a greater role in the buildup of the red sequence at lower masses, whereas other quenching processes dominate at higher masses. In addition to a statistical analysis of environmental densities, we investigate a cluster at z = 1.6, and show that the central region has an elevated fraction of quiescent objects relative to the field. Although the uncertainties are large, the environmental quenching efficiency in this cluster is consistent with that of galaxy groups and clusters at z {approx} 0. In this work we rely on photometric redshifts and describe some of the pitfalls that large redshift errors can present.

  17. The evaluation of evidence relating to traces of cocaine on banknotes.

    Science.gov (United States)

    Wilson, Amy; Aitken, Colin; Sleeman, Richard; Carter, James

    2014-03-01

    Banknotes can be seized from crime scenes as evidence for suspected association with illicit drug dealing. Tandem mass spectrometry data are available from banknotes seized in criminal investigations, as well as from banknotes from general circulation. The aim of the research is to evaluate the support provided by the data gathered in a criminal investigation for the proposition that the banknotes from which the data were obtained are associated with a person who is associated with a criminal activity related to cocaine in contrast to the proposition that the banknotes are associated with a person who is not associated with a criminal activity involving cocaine. The data considered are the peak area for the ion count for cocaine product ion m/z 105. Previous methods for assessment of the relative support for these propositions were concerned with the percentage of banknotes contaminated or assume independence of measurements of quantities between adjacent banknotes. Methods which account for an association of the quantity of drug on a banknote with that on adjacent banknotes are described. The methods are based on an autoregressive model of order one and on two versions of a nonparametric approach. The results are compared with a standard model which assumes measurements on individual banknotes are independent; there is no autocorrelation. Performance is assessed using rates of misleading evidence and a recommendation made as to which method to use. Copyright © 2014. Published by Elsevier Ireland Ltd.

  18. Tracing evolutionary relicts of positive selection on eight malaria-related immune genes in mammals.

    Science.gov (United States)

    Huang, Bing-Hong; Liao, Pei-Chun

    2015-07-01

    Plasmodium-induced malaria widely infects primates and other mammals. Multiple past studies have revealed that positive selection could be the main evolutionary force triggering the genetic diversity of anti-malaria resistance-associated genes in human or primates. However, researchers focused most of their attention on the infra-generic and intra-specific genome evolution rather than analyzing the complete evolutionary history of mammals. Here we extend previous research by testing the evolutionary link of natural selection on eight candidate genes associated with malaria resistance in mammals. Three of the eight genes were detected to be affected by recombination, including TNF-α, iNOS and DARC. Positive selection was detected in the rest five immunogenes multiple times in different ancestral lineages of extant species throughout the mammalian evolution. Signals of positive selection were exposed in four malaria-related immunogenes in primates: CCL2, IL-10, HO1 and CD36. However, selection signals of G6PD have only been detected in non-primate eutherians. Significantly higher evolutionary rates and more radical amino acid replacement were also detected in primate CD36, suggesting its functional divergence from other eutherians. Prevalent positive selection throughout the evolutionary trajectory of mammalian malaria-related genes supports the arms race evolutionary hypothesis of host genetic response of mammalian immunogenes to infectious pathogens. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  19. GREENHOUSE GASES AND MEANS OF PREVENTION

    Directory of Open Access Journals (Sweden)

    Dušica Stojanović

    2013-09-01

    Full Text Available The greenhouse effect can be defined as the consequence of increased heating of the Earth's surface, as well as the lower atmosphere by carbon dioxide, water vapor, and other trace amounts gases. It is well-known that human industrial activities have released large amounts of greenhouse gases in the atmosphere, about 900 billion tons of carbon dioxide, and it is estimated that up to 450 billion are still in the atmosphere. In comparison to greenhouse gases water vapor is one of the greatest contributors to the greenhouse effect on Earth. Many projects, as does the PURGE project, have tendences to build on the already conducted research and to quantify the positive and negative impacts on health and wellbeing of the population with greenhouse gas reduction strategies that are curently being implemented and should be increasingly applied in various sectors and urban areas, having offices in Europe, China and India.

  20. Relative enrichment of trace elements in atmospheric biomonitors - INAA results on tree bark and lichen thalli

    International Nuclear Information System (INIS)

    Pacheco, A.M.G.; Freitas, M.C.; Ventura, M.G

    2002-01-01

    Nuclear techniques, such as INAA and PIXE, are invaluable tools in environmental studies. Atmospheric biomonitoring, in particular, has been a preferential domain for their application, especially (yet not exclusively) due to their analytical robustness, minimal requirements as to sample preparation, and multi-elemental capabilities. The latter aspect is not just important for the complement they stand for each other, but also for the possibility of multiple determination, that may provide an in-depth picture of an elemental pool and, therefore, assist in data analysis, qualification and interpretation, even if some research had been originally designed to target specific, fewer elements. This paper addresses the relative magnitude of concentration patterns (by INAA) in epiphytic lichens (Parmelia spp.) and olive tree (Olea europaea Linn.) bark from an extended sampling in mainland Portugal, by looking at representative elements from natural and anthropogenic sources. Not seldom have higher plants been overlooked as indicators due to vascular and nutritional features, and also for supposedly yielding poorer analytical signals as a result of an inferior accumulation of airborne contaminants. A nonparametric assessment - correlation and sign trends - of raw and normalised (to a crustal reference) data has shown that while absolute concentrations are indeed (generally) higher in lichens, they also appear to be inflated by inputs from local circulation and/or re-suspension of previously deposited materials. On the contrary, the relative enrichment of non-crustal elements is almost invariably higher in bark than in lichens, which seems definitely at odds with the dim-accumulation scenario mentioned above. Even when the opposite occurs, the corresponding differences are non-significant but for Cl. Judging from these results, the question of signal magnitude - and the problem of biased atmospheric indication at large - could eventually stem more from the impact of soil

  1. Neurophysiological traces of interpersonal pain: How emotional autobiographical memories affect event-related potentials.

    Science.gov (United States)

    Rohde, Kristina B; Caspar, Franz; Koenig, Thomas; Pascual-Leone, Antonio; Stein, Maria

    2018-03-01

    The automatic, involuntary reactivation of disturbing emotional memories, for example, of interpersonal pain, causes psychological discomfort and is central to many psychopathologies. This study aimed at elucidating the automatic brain processes underlying emotional autobiographical memories by investigating the neurophysiological dynamics within the first second after memory reactivation. Pictures of different individualized familiar faces served as cues for different specific emotional autobiographical memories, for example, for memories of interpersonal pain and grievances or for memories of appreciation in interpersonal relationships. Nineteen subjects participated in a passive face-viewing task while multichannel electroencephalogram was recorded. Analyses of event-related potentials demonstrated that emotional memories elicited an early posterior negativity and a stronger late positive potential, which tended to be particularly enhanced for painful memories. Source estimations attributed this stronger activation to networks including the posterior cingulate and ventrolateral prefrontal cortices. The findings suggest that the reactivation of emotional autobiographical memories involves privileged automatic attention at perceptual processing stages, and an enhanced recruitment of neural network activity at a postperceptual stage sensitive to emotional-motivational processing. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  2. Measuring Strategy by Tracing Political Media Relations Tactics – A Conceptualization

    Directory of Open Access Journals (Sweden)

    Christin Schink

    2013-05-01

    Full Text Available Conceptualizing the strategic interplay of communication experts with political journalists is like being in the middle of so far conflicting approaches. The mostly economic science based literature on strategic communication management often implies a prescriptive and rational approach of decision making and behavior. From a social sciences perspective, however, the empirical transfer of mere economic rational choice models has been reasonably challenged. Although many rational choice theorists accept actor rationality to be limited rather than total and the metaphor of a “game” between the two groups is frequently used, only tentative efforts of social sciences to integrate rational choice models into the concept of strategy can be observed. This article seeks to make a case for network analysis to be applied in political media relations, as it enables the integration of approaches of strategy that have been kept separate so far. Doing so would allow strategic interactions to act as infrastructure for a descriptive analysis and environment for testing cost-benefits with the help of game theory. In this way, it allows for both a systematic integration of different strategy concepts and a comparative evaluation of their validity and explanatory power for empirical ex-post analysis in different social contexts. Developed in the German context, a possible comparative approach will be exemplified by the Russian Federation in accordance with the most different systems design.

  3. Relative enrichment of trace elements in atmospheric biomonitors - INAA results on tree bark and lichen thalli

    International Nuclear Information System (INIS)

    Pacheco, Adriano M.G.; Freitas, Maria Carmo; Ventura, Marcia G.

    2005-01-01

    Nuclear techniques, such as instrumental neutron activation analysis (INAA) or proton-induced X-ray emission (PIXE), are invaluable tools in environmental assessment. Atmospheric biomonitoring, in particular, has been a preferential domain for their application, especially (yet not exclusively) due to their analytical robustness, minimal requirements for sample preparation, and multi-elemental capabilities. The latter aspect is not just important for the complement they stand for each other, but also for the possibility of multiple determination, that may provide an in-depth picture of an elemental pool. This paper addresses the relative magnitude of concentration patterns (by INAA) in epiphytic lichens (Parmelia spp.) thalli and olive tree (Olea Europaea Linn.) bark from two sectors of a biological-monitoring network in mainland Portugal. While absolute concentrations of non-crustal elements are generally higher in lichens than in bark, the reverse of this applies, and to a larger extent, to their enrichment in each biomonitor. Raw data is thus likely to be inflated by local circulation and/or re-suspension of previously deposited materials. Judging from these results, the question of signal magnitude could eventually stem more from secondary, non-crustal inputs of local origin, and less from systemic characteristics of the present organisms. (authors)

  4. Event-related rTMS at encoding affects differently deep and shallow memory traces.

    Science.gov (United States)

    Innocenti, Iglis; Giovannelli, Fabio; Cincotta, Massimo; Feurra, Matteo; Polizzotto, Nicola R; Bianco, Giovanni; Cappa, Stefano F; Rossi, Simone

    2010-10-15

    The "level of processing" effect is a classical finding of the experimental psychology of memory. Actually, the depth of information processing at encoding predicts the accuracy of the subsequent episodic memory performance. When the incoming stimuli are analyzed in terms of their meaning (semantic, or deep, encoding), the memory performance is superior with respect to the case in which the same stimuli are analyzed in terms of their perceptual features (shallow encoding). As suggested by previous neuroimaging studies and by some preliminary findings with transcranial magnetic stimulation (TMS), the left prefrontal cortex may play a role in semantic processing requiring the allocation of working memory resources. However, it still remains unclear whether deep and shallow encoding share or not the same cortical networks, as well as how these networks contribute to the "level of processing" effect. To investigate the brain areas casually involved in this phenomenon, we applied event-related repetitive TMS (rTMS) during deep (semantic) and shallow (perceptual) encoding of words. Retrieval was subsequently tested without rTMS interference. RTMS applied to the left dorsolateral prefrontal cortex (DLPFC) abolished the beneficial effect of deep encoding on memory performance, both in terms of accuracy (decrease) and reaction times (increase). Neither accuracy nor reaction times were instead affected by rTMS to the right DLPFC or to an additional control site excluded by the memory process (vertex). The fact that online measures of semantic processing at encoding were unaffected suggests that the detrimental effect on memory performance for semantically encoded items took place in the subsequent consolidation phase. These results highlight the specific causal role of the left DLPFC among the wide left-lateralized cortical network engaged by long-term memory, suggesting that it probably represents a crucial node responsible for the improved memory performance induced by

  5. Trace gas emissions from burning Florida wetlands

    Science.gov (United States)

    Cofer, Wesley R., III; Levine, Joel S.; Lebel, Peter J.; Winstead, Edward L.; Koller, Albert M., Jr.; Hinkle, C. Ross

    1990-01-01

    Measurements of biomass burn-produced trace gases were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide normalized emission ratios for carbon monoxide, hydrogen, methane, total nonmethane hydrocarbons, and nitrous oxide were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncus roemerianus. Some interspersed scrub oak and saw palmetto were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. It is believed that the consistently low emission ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly deminished.

  6. Distribution of trace species in power plant streams: A European perspective

    International Nuclear Information System (INIS)

    Meij, R.

    1994-01-01

    In the Netherlands only pulverized coal-fired dry bottom boilers are installed. The flue gases are cleaned by high-efficiency cold-side electrostatic precipitators (ESPs) and in all large coal-fired power plants by flue-gas desulfurization (FGD) installations of the lime(stone)/gypsum process. KEMA has performed a large research program on the fate of (trace) elements at coal-fired power plants. A great deal of attention has been paid to the concentrations and distribution of trace elements in coal, in ash and in the vapor phase in the flue gases. Sixteen balance studies of coal-fired power plants, where coal imported from various countries is fired, have been performed. With the information provided by these studies the enrichment factors for the trace elements in ash and the vaporization percentage of the minor and trace elements in the flue gases have been calculated. Using these enrichment factors and vaporization percentages combined with data on the concentration in the coal, the concentrations in the ash and in the vapor phase in the flue gases can be predicted. The emission into the air of trace elements occurs in the solid state (fly ash) and in the gaseous state. The emissions in the solid state are low due to the high degree of removal in the ESPs. The emissions in the gaseous phase are, relatively speaking, more important. In an FGD both emissions are further diminished. In the next section the behavior of elements in the boiler and ESP will be discussed. The influence of the electrostatic precipitators will be reviewed the section thereafter, followed by the fate of gaseous minor and trace elements. And finally the behavior of elements in the FGD will be treated in the last section

  7. RELATIVE TRACE MINERAL BIOAVAILABILITY

    OpenAIRE

    Rchard D. Miles; Peter R. Henry

    2006-01-01

    Para determinar a eficiência de utilização de elementos minerais dietéticos, deve-se conhecer a biodisponibilidade relativa de cada elemento de um determinado ingrediente ou de uma ração completa. Análises químicas da dieta ou de um determinado ingrediente não indicam a efetividade biológica de um nutriente. Existem muitos fatores que influenciam a biodisponibilidade dos minerais, especialmente dos minerais-traço, tais como: nível de consumo do mineral, forma química, digestibilidade da dieta...

  8. Biomonitoring of air pollution in Jamaica through trace-element analysis of epiphytic plants using nuclear and related analytical techniques

    International Nuclear Information System (INIS)

    Vutchkov, M.; Lalor, G.C.; Preston, J.

    1999-01-01

    Air quality has been monitored at selected areas in Jamaica using high volume samplers. The results obtained, showed elevated levels of aluminium in bauxitic areas and very high lead concentrations in urban areas, from 5 to 35 times greater than in rural areas. The lower throughput of the conventional air particulate samplers however, restricts the air quality and health assessment on a nation-wide scale. Biomonitoring offers a cost-effective alternative to air-quality assessment if appropriate indicator species are chosen. The epiphytic lower plants such as lichens and mosses have been used as indicators of regional air quality in several European countries and USA. However, there is not enough studies on lichens and mosses in tropical countries, probably due to the lower occurrence of these species, which cover only 8% of the world's land surface. In Jamaica the epiphytic higher plants, represented by the genus Tillandsia are widely distributed, which make them along with the lichens and mosses potential site-specific bioindicators of air quality. The IAEA Co-ordinated Research Project entitled 'Biomonitoring of Air Pollution in Jamaica Through Trace-Element Analysis of Epiphytic Plants Using Nuclear And Related Analytical Techniques' will address these needs of the country. The primary purpose of the present study was to develop specific bioindicators of atmospheric air pollution in Jamaica, which will provide baseline information for health hazards assessment

  9. Use of nuclear and nuclear-related analytical techniques in studies of trace and minor elements in air pollution

    International Nuclear Information System (INIS)

    Smodis, Borut; Stropnik, Boris

    1994-01-01

    Among nuclear and nuclear-related analytical techniques, neutron activation and X-ray fluorescence analysis are particularly useful for environmental studies owing to their non-destructive character and multi-element capability. In this work, procedures for k o -standardized instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) spectrometry for trace and minor elements in air pollution studies were investigated. The methods applied were validated by the analysis of suitable reference materials. Using INAA, 20 experimentally obtained elemental values out of 21 certified and all 29 experimentally obtained values compared with 'consensus' values (for the elements where no certified numbers are available) in two SRMs were statistically indistinguishable. Also, the contents of 28 elements in candidate NIST SRM 1573a Tomato Leaves are reported. The EDXRF results were statistically indistinguishable from certified values for eight out of nine elements in NIST SRM 3087. The detection limit for this method is around at 0.1 μg cm -2 per element, so in BCR CRM No. 128, which is intended for ambient air pollution data, only Fe and Zn out of 14 elements reported in the certificate were detected with acceptable precision (i.e., 10%) owing to the very low air particulate matter loading, lying in the region of only 250 μg cm -2 . (Author)

  10. Role of trace metals in cell proliferation in the human neuroblastoma: relations with the oncogene N-myc

    International Nuclear Information System (INIS)

    Moretto, Ph.; Michelet, C.; Gouget, B.; Ortega, R.; Sergiant, C.; Llabador, Y.; Simonoff, M.; Benard, J.

    1997-01-01

    Neuroblastoma is one of the most common tumors in young children. Iron is known to be necessary for cellular proliferation. Several studies have suggested that neuroblastoma cells appear to be relatively sensitive to growth inhibition by specific Fe chelators, in vitro. In addition, it appeared that an increased serum ferritin level at diagnosis was associated with a poorer outcome than a normal level. On the other hand it was reported that untreated primary neuroblastoma had multiple copies of the N-myc oncogene. A significant association between genomic amplification and rapid tumor progression after diagnosis has been demonstrated. In order to study the relationship between iron N-myc amplification, we propose to determine the trace metal content of neuroblastoma cells. Preliminary results obtained with two distinct cell lines: SK-N-SH, a neuroblastoma cell line with a single copy of N-myc and IGR-N-91, a metastatic cell line exhibiting 60 copies of N-myc are presented. (authors)

  11. Bioaccumulation of macro- and trace elements by European frogbit (Hydrocharis morsus-ranae L.) in relation to environmental pollution.

    Science.gov (United States)

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra

    2016-02-01

    The aim of present study was to investigate the level of trace metals and macroelements in Hydrocharis morsus-ranae collected from regions differing in the degree and type of pollution. Concentrations of 17 macro- and microelements were determined in roots and shoots of European frogbit as well as in water and bottom sediments from 30 study sites. Plants differed in concentrations of elements and bioaccumulation capacity depending on the characteristics of dominant anthropogenic activities in the vicinity of the sampling site. Shoots of H. morsus-ranae growing in the vicinity of organic chemistry plants and automotive industry contained particularly high levels of Cd, Co, and S. Plants from area close to heat and power plant, former ferrochrome industry and new highway, were distinguished by the highest concentrations of Cr, Cu, and Pb. European frogbit from both these regions contained more Fe, Hg, Mn, Ni, and Zn than plants from agricultural and recreational areas. The concentrations of alkali metals and Co, Fe, and N in H. morsus-ranae were elevated in relation to the natural content in macrophytes irrespectively to their content in the environment. Based on the values of Bioaccumulation and Translocation Factors, European frogbit is an accumulator for Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn and a good candidate for phytoremediation of water polluted with Co, Cu, Hg, K, Mn, and Ni. The amount of Co and Mn removed from water and accumulated in the plant biomass during the vegetation season was considerably high.

  12. Laboratory and field based evaluation of chromatography related performance of the Monitor for AeRosols and Gases in ambient Air (MARGA)

    Science.gov (United States)

    The semi-continuous Monitor for AeRosols and Gases in Ambient air (MARGA) was evaluated using laboratory and field data with a focus on chromatography. The performance and accuracy assessment revealed various errors and uncertainties resulting from mis-identification and mis-int...

  13. Experimental study of Rayleigh scattering with a ruby laser beam: relative variation of scattered light with the number of scattering center and the gases nature

    International Nuclear Information System (INIS)

    Bayer, Charles

    1973-06-01

    The experimental variation of the scattered light with the number of scattering centers and with the refraction index of gases is in agreement with the theoretical Rayleigh scattering. A direct calibration System gives the absolute value of the Rayleigh ratio. The experimental value appears to be half of the theoretical one. (author) [fr

  14. Kinetic theory of gases

    CERN Document Server

    Kauzmann, Walter

    2012-01-01

    Monograph and text supplement for first-year students of physical chemistry focuses chiefly on the molecular basis of important thermodynamic properties of gases, including pressure, temperature, and thermal energy. 1966 edition.

  15. AC BREAKDOWN IN GASES

    Science.gov (United States)

    electron- emission (multipactor) region, and (3) the low-frequency region. The breakdown mechanism in each of these regions is explained. An extensive bibliography on AC breakdown in gases is included.

  16. Reale Gase, tiefe Temperaturen

    Science.gov (United States)

    Heintze, Joachim

    Wir werden uns in diesem Kapitel zunächst mit der van der Waals'schen Zustandsgleichung befassen. In dieser Gleichung wird versucht, die Abweichungen, die reale Gase vom Verhalten idealer Gase zeigen, durch physikalisch motivierte Korrekturterme zu berücksichtigen. Es zeigt sich, dass die van derWaals-Gleichung geeignet ist, nicht nur die Gasphase, sondern auch die Phänomene bei der Verflüssigung von Gasen und den kritischen Punkt zu beschreiben.

  17. Gases in uranium exploration

    International Nuclear Information System (INIS)

    Wright, R.J.; Pacer, J.C.

    1981-01-01

    Interest continues to grow in the use of helium and radon detection as a uranium exploration tool because, in many instances, these radiogenic gases are the only indicators of deeply buried mineralization. The origin of these gases, their migration in the ground, the type of samples and measurement techniques are discussed. Case histories of comparative tests conducted on known uranium deposits at three geologically diverse sites in the United States of America are also presented. (author)

  18. Radioactive rare gases emission at underground nuclear explosions

    International Nuclear Information System (INIS)

    Dubasov, Yu.V.

    2016-01-01

    The examples of radioactive rare gases emission at underground nuclear explosions conducted in the USSR on the Novaya Zemlya and Semipalatinsk test sites are considered. It is pointed out that in the case of evasive explosion in vertical wells without apparent radioactive gases emission the samples of subsurface gas must contain the traces of radioactive rare gases. Under the inspection of evasive explosion in horizontal workings of rock massif, one should guided by the analysis of atmospheric air samples in the inspected area [ru

  19. Chromatography related performance of the Monitor for AeRosols and GAses in ambient air (MARGA: laboratory and field-based evaluation

    Directory of Open Access Journals (Sweden)

    X. Chen

    2017-10-01

    Full Text Available Evaluation of the semi-continuous Monitor for AeRosols and GAses in ambient air (MARGA, Metrohm Applikon B.V. was conducted with an emphasis on examination of accuracy and precision associated with processing of chromatograms. Using laboratory standards and atmospheric measurements, analytical accuracy, precision and method detection limits derived using the commercial MARGA software were compared to an alternative chromatography procedure consisting of a custom Java script to reformat raw MARGA conductivity data and Chromeleon (Thermo Scientific Dionex software for peak integration. Our analysis revealed issues with accuracy and precision resulting from misidentification and misintegration of chromatograph peaks by the MARGA automated software as well as a systematic bias at low concentrations for anions. Reprocessing and calibration of raw MARGA data using the alternative chromatography method lowered method detection limits and reduced variability (precision between parallel sampler boxes. Instrument performance was further evaluated during a 1-month intensive field campaign in the fall of 2014, including analysis of diurnal patterns of gaseous and particulate water-soluble species (NH3, SO2, HNO3, NH4+, SO42− and NO3−, gas-to-particle partitioning and particle neutralization state. At ambient concentrations below  ∼  1 µg m−3, concentrations determined using the MARGA software are biased +30 and +10 % for NO3− and SO42−, respectively, compared to concentrations determined using the alternative chromatography procedure. Differences between the two methods increase at lower concentrations. We demonstrate that positively biased NO3− and SO42− measurements result in overestimation of aerosol acidity and introduce nontrivial errors to ion balances of inorganic aerosol. Though the source of the bias is uncertain, it is not corrected by the MARGA online single-point internal LiBr standard. Our results show that

  20. Chromatography related performance of the Monitor for AeRosols and GAses in ambient air (MARGA): laboratory and field-based evaluation

    Science.gov (United States)

    Chen, Xi; Walker, John T.; Geron, Chris

    2017-10-01

    Evaluation of the semi-continuous Monitor for AeRosols and GAses in ambient air (MARGA, Metrohm Applikon B.V.) was conducted with an emphasis on examination of accuracy and precision associated with processing of chromatograms. Using laboratory standards and atmospheric measurements, analytical accuracy, precision and method detection limits derived using the commercial MARGA software were compared to an alternative chromatography procedure consisting of a custom Java script to reformat raw MARGA conductivity data and Chromeleon (Thermo Scientific Dionex) software for peak integration. Our analysis revealed issues with accuracy and precision resulting from misidentification and misintegration of chromatograph peaks by the MARGA automated software as well as a systematic bias at low concentrations for anions. Reprocessing and calibration of raw MARGA data using the alternative chromatography method lowered method detection limits and reduced variability (precision) between parallel sampler boxes. Instrument performance was further evaluated during a 1-month intensive field campaign in the fall of 2014, including analysis of diurnal patterns of gaseous and particulate water-soluble species (NH3, SO2, HNO3, NH4+, SO42- and NO3-), gas-to-particle partitioning and particle neutralization state. At ambient concentrations below ˜ 1 µg m-3, concentrations determined using the MARGA software are biased +30 and +10 % for NO3- and SO42-, respectively, compared to concentrations determined using the alternative chromatography procedure. Differences between the two methods increase at lower concentrations. We demonstrate that positively biased NO3- and SO42- measurements result in overestimation of aerosol acidity and introduce nontrivial errors to ion balances of inorganic aerosol. Though the source of the bias is uncertain, it is not corrected by the MARGA online single-point internal LiBr standard. Our results show that calibration and verification of instrument accuracy

  1. Linking genes to ecosystem trace gas fluxes in a large-scale model system

    Science.gov (United States)

    Meredith, L. K.; Cueva, A.; Volkmann, T. H. M.; Sengupta, A.; Troch, P. A.

    2017-12-01

    Soil microorganisms mediate biogeochemical cycles through biosphere-atmosphere gas exchange with significant impact on atmospheric trace gas composition. Improving process-based understanding of these microbial populations and linking their genomic potential to the ecosystem-scale is a challenge, particularly in soil systems, which are heterogeneous in biodiversity, chemistry, and structure. In oligotrophic systems, such as the Landscape Evolution Observatory (LEO) at Biosphere 2, atmospheric trace gas scavenging may supply critical metabolic needs to microbial communities, thereby promoting tight linkages between microbial genomics and trace gas utilization. This large-scale model system of three initially homogenous and highly instrumented hillslopes facilitates high temporal resolution characterization of subsurface trace gas fluxes at hundreds of sampling points, making LEO an ideal location to study microbe-mediated trace gas fluxes from the gene to ecosystem scales. Specifically, we focus on the metabolism of ubiquitous atmospheric reduced trace gases hydrogen (H2), carbon monoxide (CO), and methane (CH4), which may have wide-reaching impacts on microbial community establishment, survival, and function. Additionally, microbial activity on LEO may facilitate weathering of the basalt matrix, which can be studied with trace gas measurements of carbonyl sulfide (COS/OCS) and carbon dioxide (O-isotopes in CO2), and presents an additional opportunity for gene to ecosystem study. This work will present initial measurements of this suite of trace gases to characterize soil microbial metabolic activity, as well as links between spatial and temporal variability of microbe-mediated trace gas fluxes in LEO and their relation to genomic-based characterization of microbial community structure (phylogenetic amplicons) and genetic potential (metagenomics). Results from the LEO model system will help build understanding of the importance of atmospheric inputs to

  2. Speciation of trace elements in biological samples by nuclear analytical and related techniques coupled with chemical and biochemical separation

    International Nuclear Information System (INIS)

    Chen, C.Y.; Gao, Y.X.; Li, B.; Yu, H.W.; Li, Y.F.; Sun, J.; Chai, Z.F.

    2005-01-01

    indicated quite different distribution patterns between malignant and their adjacent normal liver -tissues by using online technique of HPLC-ICP-MS or offline detection of gel electrophoresis with SRXRF. The imbalances of trace elements related to oxidative stress, e.g. Se-dependent glutathione peroxidase and thioredoxin reductase, Cu Zn-superoxide dismutase, Fe-dependent catalase, were also discussed. In another cohort study, Se and Hg species in human serum, urine or hair samples can be elucidated by reverse phase HPLC-ICP-MS, providing new data for interaction between Se and Hg under Hg exposure. The coordination status of Hg can be further obtained by EXAFS study, In conclusion, the information of elemental speciation based on the application of INAA, HPLC-ICP-MS, XRF, and so on would help to understand their biological function, especially in the occurrence and development of certain diseases in vivo.

  3. Development of monitoring and control technology based on trace gas monitoring. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Liebowitz, B.

    1997-07-01

    Trace gases are generated by many biological reactions. During anaerobic decomposition, trace levels of hydrogen (H{sub 2}) and carbon monoxide (CO) gases are produced. It was shown previously that these trace gases are intrinsically related to the biochemical reactions occurring and, therefore, offer promise for on-line process monitoring and control. This work was designed to test how effectively hydrogen and CO could be to monitor high-rate anaerobic systems that has significant mass transfer and complex hydraulics. An experimental program was designed to examine the behavior of an upflow anaerobic sludge blanket (UASB) reactor system under steady state and in response to organic loading perturbations. The responses of trace gases CO and H{sub 2} were tracked using an on-line, real-time gas-monitoring system linked to a computer-controlled data acquisition package. Data on conventional process parameters such as pH, chemical oxygen demand (COD), volatile fatty acids (VFAs) were concurrently collected. Monitoring of conventional process indicators (i.e., pH, VFA, gas production) and trace gas (H{sub 2} and CO) indicators was conducted using a matrix of nine different steady-state OLRs (4-23 kg COD/m{sup 3} -d) and system HRTs (0.5 to 2.5 days) was performed to determine any correlation among the indicators. Of OLR, HRT, and influent COD, only OLR had any significant influence on the process indicators examined. All parameters except methane increased with increases in OLR; methane decreased with increased OLR. The OLR and gas production rate (GP) were observed to be linearly correlated.

  4. Trace analysis

    International Nuclear Information System (INIS)

    Warner, M.

    1987-01-01

    What is the current state of quantitative trace analytical chemistry? What are today's research efforts? And what challenges does the future hold? These are some of the questions addressed at a recent four-day symposium sponsored by the National Bureau of Standards (NBS) entitled Accuracy in Trace Analysis - Accomplishments, Goals, Challenges. The two plenary sessions held on the first day of the symposium reviewed the history of quantitative trace analysis, discussed the present situation from academic and industrial perspectives, and summarized future needs. The remaining three days of the symposium consisted of parallel sessions dealing with the measurement process; quantitation in materials; environmental, clinical, and nutrient analysis; and advances in analytical techniques

  5. Trace Gas Quantification with Small Unmanned Aerial Systems

    Science.gov (United States)

    Schuyler, T. J.; Guzman, M. I.; Bailey, S.; Jacob, J.

    2017-12-01

    Measurements of atmospheric composition are generally performed with advanced instrumentation from ground stations using tall towers and weather balloons or with manned aircraft. Unmanned aerial systems (UAS) are a promising technology for atmospheric monitoring of trace atmospheric gases as they can bridge the gap between the regions of the atmospheric boundary layer measured by ground stations and aircraft. However, in general, the sophisticated instrumentation required for these measurements are heavy, preventing its deployment with small UAS. In order to successfully detect and quantify these gases, sensor packages aboard UAS must be lightweight, have low-power consumption, and possess limits of detection on the ppm scale or below with reasonably fast response times. Thus, a new generation of portable instrument is being developed in this work to meet these requirements employing new sensing packages. The cross sensitivity of these sensors to several gases is examined through laboratory testing of the instrument under variable environmental conditions prior to performing field measurements. Datasets include timestamps with position, temperature, relative humidity, pressure, along with variable mixing ratio values of important greenhouse gases. The work will present an analysis of the results gathered during authorized flights performed during the second CLOUD-MAP§ field campaign held in June 2017. §CLOUD-MAP: Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics, a 4-year NSF funded effort.

  6. Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black

    Directory of Open Access Journals (Sweden)

    Bosak, Z.

    2009-01-01

    Full Text Available This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV oxide, carbon(II oxide, hydrogen, methane, hydrogen sulfide, nitrogen, oxygen, and water vapor.The quantitative composition and lower caloric value of process tail gases change depending on the type of feedstock used in the production, as well as the type of process. The lower caloric value of process tail gases is relatively small with values ranging between 1500 and 2300 kJ m–3.In the conventional production of oil-furnace carbon black, process tail gases purified from carbon black dust are freely released into the atmosphere untreated. In this manner, the process tail gases pollute the air in the town of Kutina, because their quantitative values are much higher than the prescribed emissions limits for hydrogen sulfide and carbon(II oxide. A logical solution for the prevention of such air pollution is combustion of the process tail gases, i. e. their thermal oxidation. For this purpose, a specially designed flare system has been developed. Consuming minimum amounts of natural gas needed for oxidation, the flare system is designed to combust low caloric process tail gases with 99 % efficiency. Thus, the toxic and flammable components of the tail gases (hydrogen sulfide, hydrogen, carbon(II oxide, methane and other trace hydrocarbons would be transformed into environmentally acceptable components (sulfur(IV oxide, water, carbon(IV oxide and nitrogen(IV oxide, which are in compliance with the emissions limit values prescribed by law.Proper operation of this flare system in the production of oil-furnace carbon black would solve

  7. Nuclear traces in glass

    International Nuclear Information System (INIS)

    Segovia A, M. de N.

    1978-01-01

    The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

  8. Granular Gases: Probing the Boundaries of Hydrodynamics

    International Nuclear Information System (INIS)

    Goldhirsch, I.

    1999-01-01

    The dissipative nature of the particle interactions in granular systems renders granular gases mesoscopic and bearing some similarities to regular gases in the ''continuum transition regime'' where shear rates and/or thermal gradients are very large). The following properties of granular gases support the above claim: (i). Mean free times are of the same order as macroscopic time scales (inverse shear rates); (ii). Mean free paths can be macroscopic and comparable to the system's dimensions; (iii). Typical flows are supersonic; (iv). Shear rates are typically ''large''; (v). Stress fields are scale (resolution) dependent; (vi). Burnett and super-Burnett corrections to both the constitutive relations and the boundary conditions are of importance; (vii). Single particle distribution functions can be far from Gaussian. It is concluded that while hydrodynamic descriptions of granular gases are relevant, they are probing the boundaries of applicability of hydrodynamics and perhaps slightly beyond

  9. Determination of trace elements and heavy metals in agricultural products cultivated at the Rimac river valley in Lima city using nuclear and related analytical techniques

    OpenAIRE

    Bedregal, Patricia; Torres, Blanca; Olivera, Paula; Mendoza, Pablo; Ubillús, Marco; Creed-Kanashiro, H.; Penny, M.; Junco, J.; Ganoza, L.

    2004-01-01

    There are strong indications that the Rimac river valley is being contaminated with heavy metals and an excess of trace elements that come from some industrial and mining activities developed along the Rimac river valley. The agricultural products cultivated there in could be suffering the same effect. Nuclear and related analytical techniques will play an important role in the study of pollution by providing information concerning the degree of contamination in some agricultural products cul...

  10. Curiosities of arithmetic gases

    International Nuclear Information System (INIS)

    Bakas, I.; Bowick, M.J.

    1991-01-01

    Statistical mechanical systems with an exponential density of states are considered. The arithmetic analog of parafermions of arbitrary order is constructed and a formula for boson-parafermion equivalence is obtained using properties of the Riemann zeta function. Interactions (nontrivial mixing) among arithmetic gases using the concept of twisted convolutions are also introduced. Examples of exactly solvable models are discussed in detail

  11. Radiation effects in gases

    International Nuclear Information System (INIS)

    Leonhardt, J.W.

    1985-01-01

    Problems in the studies of radiation effects in gases are discussed. By means of ionization- excitation- and electron-capture yields various applications are characterized: ionization detectors, X-ray detectors, radionuclide battery, and radiation-induced chemical gas-phase reactions. Some new results of basic research in respect to the SO 2 oxidation are discussed. (author)

  12. The greenhouse effect gases

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the greenhouse effect gases. It presents the greenhouses effect as a key component of the climate system, the impacts of the human activity, the foreseeable consequences of global warming, the Kyoto protocol and Total commitment in the domain. (A.L.B.)

  13. Development of an integrated energy concept: Assessment of the potential for the reduction of emissions of climate effective trace gases in the field of rational energy use in the old Laender. Appendix Vol. 1. Sector households. Sector small consumers

    International Nuclear Information System (INIS)

    Bonhoff, C.; Luther, T.

    1993-11-01

    The calculated scenarios have shown that especially in the sector households large potentials for the reduction of CO 2 -emissions could be realised, provided that the necessary marginal conditions are created. In this respect the approach of an energy service reveals that energy conservation is possible without giving up comfort. The conversation potentials are characterised by an economic cost effectiveness. Their realisation must be the aim of an energy policy that conserves the resources and minimises the risk. In this respect the attention must not only be drawn to those energy conservation potentials, which can be achieved by an improvement of the technical efficiency, as it has been demonstrated in the scenario efficiency. According to the scenario ecological structure policy the conservation potentials related to the use must be the main focus of the investigation instead, because they can be very often realised ''free of charge''. At the same time they can be the beginning of a change of consciousness of the people towards a behaviour, that better conserves the resources. (orig./UA) [de

  14. Safety related investigations of the VVER-1000 reactor type by the coupled code system TRACE/PARCS

    International Nuclear Information System (INIS)

    Jaeger, Wadim; Lischke, Wolfgang; Sanchez Espinoza, Victor Hugo

    2007-01-01

    This study was performed at the Institute of Reactor Safety at the Research Center Karlsruhe. It is embedded in the ongoing investigations of the international code application and maintenance program (CAMP) for qualification and validation of system codes like TRACE [1] and PARCS [2]. The predestinated reactor type for the validation of these two codes was the Russian designed VVER-1000 because the OECD/NEA VVER-1000 Coolant Transient Benchmark Phase 2 [3] includes detailed information of the Bulgarian nuclear power plant (NPP) Kozloduy unit 6. The posttest-investigations of a coolant mixing experiment have shown that the predicted parameters (coolant temperature, pressure drop, etc.) are in good agreement to the measured data. The coolant mixing pattern especially in the downcomer has been also reproduced quiet well by TRACE. The coupled code system TRACE/PARCS which was applied on a postulated main steam line break (MSLB) provides good results compared to reference values and the ones of other participants of the benchmark. It can be pointed out that the developed three-dimensional nodalisation of the reactor pressure vessel (RPV) is appropriate for the description of transients where the thermal-hydraulics and the neutronics are strongly linked. (author)

  15. Simultaneous Photoacoustic and Photopyroelectric Detection of Trace Gas Emissions from Some Plant Parts and Their Related Essential Oils in a Combined Detection Cell

    Science.gov (United States)

    Abu-Taha, M. I.; Abu-Teir, M. M.; Al-Jamal, A. J.; Eideh, H.

    The aim of this work was to establish the feasibility of the combined photoacoustic (PA) and photopyroelectric (PPE) detection of the vapours emitted from essential oils and their corresponding uncrushed leaves or flowers. Gas traces of jasmine (Jessamine (Jasminum)), mint (Mentha arvensis L.) and Damask rose (Rosa damascena Miller) and their essential oils were tested using a combined cell fitted with both a photopyroelectric film (PVDF) and a microphone in conjunction with a pulsed wideband infrared source (PWBS) source. Infrared PA and PPE absorbances were obtained simultaneously at room temperatures with excellent reproducibility and high signal-to-noise ratios. Significant similarities found between the PA and PPE spectra of the trace gas emissions of plant parts, i.e., flowers or leaves and their related essential oils show the good correlation of their emissions and that both effects are initiated by the same absorbing molecules.

  16. Analysis of electron interactions in dielectric gases

    International Nuclear Information System (INIS)

    Olivet, Aurelio; Duque, Daniel; Vega, Lourdes F.

    2007-01-01

    We present and discuss results concerning electron interactions processes of dielectric gases and their relationship with the macroscopic behavior of these gases, in particular, with their dielectric strength. Such analysis is based on calculating energies of reactions for molecular ionization, dissociative ionization, parent negative ion formation, and dissociative electron attachment processes. We hypothesize that the estimation of the required energy for a reduced number of processes that take place in electrically stressed gases could be related to the gas' capability to manage the electron flow during an electrical discharge. All calculations were done with semiempirical quantum chemistry methods, including an initial optimization of molecular geometry and heat of formation of the dielectric gases and all of species that appear during electron interaction reactions. The performance of semiempirical methods Austin model 1 and Parametric model 3 (PM3) was compared for several compounds, PM3 being superior in most cases. Calculations performed for a sample of nine dielectric gases show that electron attachment and detachment processes occur in different energy bands that do not overlap for any value of the dielectric strength. We have also analyzed the relationship between dielectric strength and two physical properties: electron affinity and ionization energy. Calculations performed for 43 dielectric gases show no clear correlation between them, although certain guidelines for the qualitative estimation of dielectric strength can still be assessed

  17. The use of INAA for the determination of trace elements, in particular cadmium, in plastics in relation to the enforcement of pollution standards

    International Nuclear Information System (INIS)

    Bode, P.

    1993-01-01

    Many plastic products have relatively short life cycles. Upon final destruction, inorganic additives used for pigmentation, as polymer stabilizer or as flame retarding agent are being released to the environment. In a rapidly increasing way governmental authorities are setting limits to the use of inorganic additives, in particular cadmium, in plastics. INAA has attractive characteristics which may make authorities decide to select it for the control programs in relation to the enforcement of pollution standards. An evaluation is made of the use of INAA for such analysis; analysis protocols, sensitivities, and observed levels of other trace elements are being discussed. (author) 2 refs.; 2 tabs

  18. Observations of trace gases and aerosols over the Indian Ocean ...

    Indian Academy of Sciences (India)

    analyzer operates on the principle of infrared absorption at ... The difference between the weight of filter paper before and .... with enhanced biomass burning during dry El-Ni˜no periods (e.g. ..... port and dispersion model and/or READY web-.

  19. Climate aspects of radioactive trace gases, especially krypton-85

    International Nuclear Information System (INIS)

    Kollert, R.; Butzin, M.

    1990-01-01

    The amount of krypton 85 currently present in the atmosphere is 3.300 Peta Bq. This atmospheric krypton contamination stems from atom bomb tests of the past and from nuclear power plants as well as spent fuel reprocessing plants. The paper investigates the air-electric and air-chemical impact of Kr-85 on the atmosphere and makes a forecast of the future Kr-85 contamination. (DG) [de

  20. Aerial sampling using drones for measuring trace gases

    Science.gov (United States)

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Lin, Ming-Ren; Ou-Yang, Chang-Feng; Pan, Xiang-Xu; Lin, Neng-Huei

    2017-04-01

    Aerial and ground-level samples were simultaneously collected at the northern tip of Taiwan, Cape Fuguei, which is commonly served as a receptor site to receive air parcels from East Asia, Asian continent, the northwest Pacific Ocean and the island of Taiwan itself. Both aerial and surface samples were analyzed for 106 volatile organic compounds (VOCs) and divided into three categories as follows: 1. the total concentrations of 106 VOC (T-VOC) at 300-m height that are lower than the T-VOC level at the surface (Category A), 2. T-VOC concentrations at 300-m that are higher than those at the surface (Category B), and 3. comparable concentrations (Category C). Ten VOCs were exploited as tracers for a variety of emission sources linking to possible sources and transport routes of airborne pollutants. The first two categories A and B showed significant differences in the observed composition and concentrations of tracers between aerial and ground-level samples, implying that the pollutants at different heights may have resulted from different sources and poor air mixing, despite only a 300-m difference in vertical height. In contrast, Category C showed good vertical mixing, as indicated by the comparable concentrations between the aerial and surface measurements. Since the three categories occurred in specific meteorological conditions (between, prior to, and after cold fronts), respectively, it suggests that varied prevailing meteorology controlled the distribution and transport of airborne pollutants. Unlike sampling commonly performed at the surface, this study uses aerial sampling to demonstrate that layered structures under different meteorological conditions. Sampling aloft in lower boundary layer avoids samples being over-influenced by the close-by surface sources such as traffic to reveal signatures of a broader region.

  1. Intraoral gothic arch tracing.

    Science.gov (United States)

    Rubel, Barry; Hill, Edward E

    2011-01-01

    In order to create optimum esthetics, function and phonetics in complete denture fabrication, it is necessary to record accurate maxillo-mandibular determinants of occlusion. This requires clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Any errors made while taking maxillo-mandibular jaw relation records will result in dentures that are uncomfortable and, possibly, unwearable. The application of a tracing mechanism such as the Gothic arch tracer (a central bearing device) is a demonstrable method of determining centric relation. Intraoral Gothic arch tracers provide the advantage of capturing VDO and CR in an easy-to-use technique for practitioners. Intraoral tracing (Gothic arch tracing) is a preferred method of obtaining consistent positions of the mandible in motion (retrusive, protrusive and lateral) at a comfortable VDO.

  2. Fuel gases in Algeria

    International Nuclear Information System (INIS)

    Arachiche, B.; Elandaloussi, H.

    1996-01-01

    For a country like Algeria, fuel gases represent an important economical challenge. To answer the increasing energy demand in the transportation sector, the use of fuel gases allows to preserve the petroleum reserves and to create specific industrial structures devoted to LPG-f (liquefied petroleum gas-fuel) and NGV (natural gas for vehicles). This paper presents the energy policy of Algeria, its reserves, production, and exportations of hydrocarbons and the internal rational use of energy sources according to its economic and environmental policy and to its internal needs. The energy consumption of Algeria in the transportation sector represents 2/3 of the petroleum products consumed in the internal market and follows a rapid increase necessary to the socio-economic development of the country. The Algerian experience in fuel gases is analysed according to the results of two successive experimentation periods for the development of NGV before and after 1994, and the resulting transportation and distribution network is described. The development of LPG-f has followed also an experimental phase for the preparation of regulation texts and a first statement of the vehicles conversion to LPG-f is drawn with its perspectives of development according to future market and prices evolutions. (J.S.)

  3. A clinico-radiographic study to compare and co-relate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in completely edentulous patients.

    Science.gov (United States)

    Shetty, Sanath; Kunta, Mythili; Shenoy, Kamalakanth

    2018-01-01

    The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in edentulous patients. Twelve completely edentulous patients were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture till jaw relation were carried out. Intraoral gothic arch tracing and protrusive interocclusal records were obtained for each patient. Protrusive interocclusal record was used to program the Hanau Wide-Vue semi-adjustable articulator, thus obtaining the sagittal condylar guidance angle. Using RadiAnt DICOM software, on the orthopantomogram obtained for each patient in the study, two reference lines were drawn. The Frankfort's horizontal plane and the mean curvature line (joining the most superior and the inferior points on the glenoid fossa curvature) were drawn. The mean curvature line was extended to intersect the Frankfort's horizontal plane, thus obtaining the radiographic sagittal condylar guidance angle. The condylar guidance angles obtained by these two methods were compared and subjected to paired t -test. There was no statistically significant difference between the sagittal condylar guidance angles obtained between right and left sides with intraoral gothic arch tracing and radiographic methods ( P = 0.107 and 0.07, respectively). Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used for programming semi-adjustable articulators.

  4. Modulation of capillary condensation by trace component

    Directory of Open Access Journals (Sweden)

    Shiqi Zhou

    2011-06-01

    Full Text Available Impact of trace component on capillary condensation (CC is investigated systematically using a classical density functional theory. It is discovered that (i presence of the trace component makes the CC to occur at much lower condensation pressure than when its absence; (ii Lennard-Jones potential parameters like size parameter and energy parameter of the trace component, and its concentration in the bulk adsorption system, show their effects the most remarkably within a particular range beyond which the effects eventually become insignificant. The present discoveries have implications in low pressure storage of gases, separation and enrichment of low concentration component, and easy control of CC transition, etc.

  5. Prediction of friction coefficients for gases

    Science.gov (United States)

    Taylor, M. F.

    1969-01-01

    Empirical relations are used for correlating laminar and turbulent friction coefficients for gases, with large variations in the physical properties, flowing through smooth tubes. These relations have been used to correlate friction coefficients for hydrogen, helium, nitrogen, carbon dioxide and air.

  6. Miniaturized Laser Heterodyne Radiometer (LHR) for Measurements of Greenhouse Gases in the Atmospheric Column

    Science.gov (United States)

    Steel, Emily; McLinden, Matthew

    2012-01-01

    This passive laser heterodyne radiometer (LHR) instrument simultaneously measures multiple trace gases in the atmospheric column including carbon dioxide (CO2) and methane (CH4), and resolves their concentrations at different altitudes. This instrument has been designed to operate in tandem with the passive aerosol sensor currently used in AERONET (an established network of more than 450 ground aerosol monitoring instruments worldwide). Because aerosols induce a radiative effect that influences terrestrial carbon exchange, simultaneous detection of aerosols with these key carbon cycle gases offers a uniquely comprehensive measurement approach. Laser heterodyne radiometry is a technique for detecting weak signals that was adapted from radio receiver technology. In a radio receiver, a weak input signal from a radio antenna is mixed with a stronger local oscillator signal. The mixed signal (beat note, or intermediate frequency) has a frequency equal to the difference between the input signal and the local oscillator. The intermediate frequency is amplified and sent to a detector that extracts the audio from the signal. In the LHR instrument described here, sunlight that has undergone absorption by the trace gas is mixed with laser light at a frequency matched to a trace gas absorption feature in the infrared (IR). Mixing results in a beat signal in the RF (radio frequency) region that can be related to the atmospheric concentration. For a one-second integration, the estimated column sensitivities are 0.1 ppmv for CO2, and Greenhouse gases Observational SATellite). The only network that currently measures CO2 and CH4 in the atmospheric column is TCCON (Total Carbon Column Observing Network), and only two of its 16 operational sites are in the United States. TCCON data is used for validation of GOSAT data, and will be used for OCO-2 validation. While these Fourier-transform spectrometers (FTS) can measure the largest range of trace gases, the network is severely limited

  7. Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).

    Science.gov (United States)

    Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.

    2012-04-01

    Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation

  8. TraceContract

    Science.gov (United States)

    Kavelund, Klaus; Barringer, Howard

    2012-01-01

    TraceContract is an API (Application Programming Interface) for trace analysis. A trace is a sequence of events, and can, for example, be generated by a running program, instrumented appropriately to generate events. An event can be any data object. An example of a trace is a log file containing events that a programmer has found important to record during a program execution. Trace - Contract takes as input such a trace together with a specification formulated using the API and reports on any violations of the specification, potentially calling code (reactions) to be executed when violations are detected. The software is developed as an internal DSL (Domain Specific Language) in the Scala programming language. Scala is a relatively new programming language that is specifically convenient for defining such internal DSLs due to a number of language characteristics. This includes Scala s elegant combination of object-oriented and functional programming, a succinct notation, and an advanced type system. The DSL offers a combination of data-parameterized state machines and temporal logic, which is novel. As an extension of Scala, it is a very expressive and convenient log file analysis framework.

  9. Volcanic Gases and Hot Spring Water to Evaluate the Volcanic Activity of the Mt. Baekdusan

    Science.gov (United States)

    Yun, S. H.; Lee, S.; Chang, C.

    2017-12-01

    This study performed the analysis on the volcanic gases and hot spring waters from the Julong hot spring at Mt. Baekdu, also known as Changbaishan on the North Korea(DPRK)-China border, during the period from July 2015 to August 2016. Also, we confirmed the errors that HCO3- concentrations of hot spring waters in the previous study (Lee et al. 2014) and tried to improve the problem. Dissolved CO2 in hot spring waters was analyzed using gas chromatograph in Lee et al.(2014). Improving this, from 2015, we used TOC-IC to analysis dissolved CO2. Also, we analyzed the Na2CO3 standard solutions of different concentrations using GC, and confirmed the correlation between the analytical concentrations and the real concentrations. However, because the analytical results of the Julong hot spring water were in discord with the estimated values based on this correlation, we can't estimate the HCO3-concentrations of 2014 samples. During the period of study, CO2/CH4 ratios in volcanic gases are gradually decreased, and this can be interpreted in two different ways. The first interpretation is that the conditions inside the volcanic edifice are changing into more reduction condition, and carbon in volcanic gases become more favorable to distribute into CH4 or CO than CO2. The second interpretation is that the interaction between volcanic gases and water becomes greater than past, and the concentrations of CO2which have much higher solubility in water decreased, relatively. In general, the effect of scrubbing of volcanic gas is strengthened during the quiet periods of volcanic activity rather than active periods. Meanwhile, the analysis of hot spring waters was done on the anion of acidic gases species, the major cations, and some trace elements (As, Cd, Re).This work was funded by the Korea Meteorological Administration Research and Development Program under Grant KMIPA 2015-3060.

  10. Long-term prognosis of diabetic patients with myocardial infarction: relation to antidiabetic treatment regimen. The TRACE Study Group

    DEFF Research Database (Denmark)

    Gustafsson, I; Hildebrandt, P; Seibaek, M

    2000-01-01

    a higher prevalence of known cardiovascular disease. Even though the diabetic patients had the same frequency of ST-segment elevation on the electrocardiogram and the same admission delay, treatment with thrombolysis and aspirin was less frequently prescribed to the diabetic patients than to patients......AIMS: The present study was performed to evaluate pre-admission history, presentation, initial treatment and long-term mortality in patients with myocardial infarction and diabetes. METHODS AND RESULTS: Between 1990 and 1992, 6676 patients with acute myocardial infarction were screened for entry...... into the Trandolapril Cardiac Evaluation (TRACE) study. In this cohort 719 (11%) of the patients had a history of diabetes. Among the diabetic patients 19% were treated with insulin, 52% with oral hypoglycaemic agents and 29% with diet only. The diabetic patients were slightly older, more likely to be female and had...

  11. On Classical Ideal Gases

    Directory of Open Access Journals (Sweden)

    Laurent Chusseau

    2013-02-01

    Full Text Available We show that the thermodynamics of ideal gases may be derived solely from the Democritean concept of corpuscles moving in vacuum plus a principle of simplicity, namely that these laws are independent of the laws of motion, aside from the law of energy conservation. Only a single corpuscle in contact with a heat bath submitted to a z and t-invariant force is considered. Most of the end results are known but the method appears to be novel. The mathematics being elementary, the present paper should facilitate the understanding of the ideal gas law and of classical thermodynamics even though not-usually-taught concepts are being introduced.

  12. Effect of an Organic Trace Mineral Premix on the Semen Quality, Testicular Morphology and Gene Expression Related to Testosterone Synthesis of Male Broiler Breeders

    Directory of Open Access Journals (Sweden)

    T Shan

    Full Text Available ABSTRACT In order to investigate the effect of organic trace minerals premix (OTM on the reproductive performance of breeder roosters, a total of 240 San Huang roosters (23 weeks of age were randomly divided into two treatments with six replicates of 20 roosters each. The first group (n = 120 was fed a basal diet containing an inorganic trace minerals premix (ITM and the other group (n = 120 was fed the basal diet in which ITM was replaced by OTM. The experiment period was 22 weeks. Semen from one randomly-selected rooster per replicate was collected two weeks after the beginning of the experiment and other 10 times every two weeks. Another rooster per replicate was randomly selected at 30, 35, and 45 weeks of age, and sacrificed. Results showed that OTM did not affect relative organ weights. There was a significant increase in semen parameters in OTM group (p<0.05, such as semen volume, semen density, and semen motility from 31 to 35 weeks. OTM-fed roosters presented higher serum testosterone levels at 45 weeks of age, as well as higher testicular mRNA expression of the genes 3-beta dehydrogenase 2 (HSD3B2 and cytochrome P450 17A1 (CYP17A1 in the OTM-fed group at 45 weeks of age compared with those fed ITM (p<0.05. Considering the results of the present study, it was concluded that feeding organic instead of inorganic trace minerals to male broilers breeders improves semen quality, which may be attributed to their better testicular development and higher expression of enzymes related to testosterone synthesis.

  13. Temperature and Concentration Traces of Spray Flows During Motion in a Flame

    Directory of Open Access Journals (Sweden)

    Antonov Dmitry V.

    2016-01-01

    Full Text Available Heat and mass transfer models are developed on the base of experimental data and using Ansys Fluent software. These models allow prediction of the temperature and concentration traces of droplets. Transfer mechanisms of water droplets from different flames of flammable liquid (ethanol, kerosene И benzine with temperature gases 450–850 К are analyzed. The paper considers aerosol flows with droplets sizes of 0.04–0.4 mm and concentration of 3.8·10-5 –10.3·10-5 m3 of droplets/m3 of gas. The maximum gas temperature reduction in the trace of a moving liquid is ranged from 850 K to 600 K. The times of keeping the low temperature of the gas-vapor mixture in the droplets trace are from 13 s to 25 s relative to the initial gas temperature.

  14. Removing radioactive noble gases from nuclear process off-gases

    International Nuclear Information System (INIS)

    Lofredo, A.

    1977-01-01

    A system is claimed for separating, concentrating and storing radioactive krypton and xenon in the off-gases from a boiling water reactor, wherein adsorption and cryogenic distillation are both efficiently used for rapid and positive separation and removal of the radioactive noble gases, and for limiting such gases in circulation in the system to low inventory at all times, and wherein the system is self-regulating to eliminate operator options or attention

  15. Measuring Viscosities of Gases at Atmospheric Pressure

    Science.gov (United States)

    Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini

    1987-01-01

    Variant of general capillary method for measuring viscosities of unknown gases based on use of thermal mass-flowmeter section for direct measurement of pressure drops. In technique, flowmeter serves dual role, providing data for determining volume flow rates and serving as well-characterized capillary-tube section for measurement of differential pressures across it. New method simple, sensitive, and adaptable for absolute or relative viscosity measurements of low-pressure gases. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.

  16. Indoor air pollution caused by geothermal gases

    International Nuclear Information System (INIS)

    Durand, Michael

    2006-01-01

    This paper discusses the little-known but potentially serious indoor air quality problems that may occur where buildings are constructed on geothermal ground. The main problems are related to seepage of carbon dioxide, hydrogen sulphide, radon and other gases from soil cavities directly into indoor air through perforations in the structure. These gases present a health hazard, and hydrogen sulphide, which is particularly corrosive, may cause problems electrical and electronic systems. Counter-measures are not always effective, so developments in such areas should only be undertaken with a clear understanding of site-specific issues and their possible solutions. (author)

  17. Bose-Einstein condensation of atomic gases

    International Nuclear Information System (INIS)

    Anglin, J. R.; Ketterle, W.

    2003-01-01

    The early experiments on Bose-Einstein condensation in dilute atomic gases accomplished three longstanding goals. First, cooling of neutral atoms into their motional state, thus subjecting them to ultimate control, limited only by Heisenberg uncertainty relation. Second, creation of a coherent sample of atoms, in which all occupy the same quantum states, and the realization of atom lasers - devices that output coherent matter waves. And third, creation of gaseous quantum fluid, with properties that are different from the quantum liquids helium-3 and helium-4. The field of Bose-Einstein condensation of atomic gases has continued to progress rapidly, driven by the combination of new experimental techniques and theoretical advances. The family of quantum degenerate gases has grown, and now includes metastable and fermionic atoms. condensates have become an ultralow-temperature laboratory for atom optics, collisional physics and many-body physics, encompassing phonons, superfluidity, quantized vortices, Josephson junctions and quantum phase transitions. (author)

  18. Evaluation of trace element and mineral status and related to levels of amino acid in children with phenylketonuria.

    Science.gov (United States)

    Gok, Fazilet; Ekin, Suat; Dogan, Murat

    2016-07-01

    The aim of the present study was to examine trace elements (Zn, Cu, Mn, Se, Fe, Co, Cr, Ni, Cd, Pb), minerals (Ca, Mg, K), amino acids status in children with phenylketonuria and also whether they were correlated with each other in phenylketonuric patients. It has been found out that the HPA group was significantly lower than the control group with regards to Zn, Se, K, Ca, Mg and Zn/Cr levels (p<0.001, p<0.01, p<0.001, p<0.01, p<0.01 and p<0.001 respectively). In the patients with HPA, significantly strong positive correlations were observed between magnesium and calcium (r=0.791; p=0.001), also, indicates negative significant correlation between the concentrations of magnesium and phenylalanine (r=-0.591; p=0.026). The results of this study showed that, in the HPA group, phenylalanine-Mg relationship found, the presence of disease will in the evaluation of phenylalanine and other amino acids, together with the value of magnesium is required to consider. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Analysis of Trace Pharmaceuticals and Related Compounds in Municipal Wastewaters by Preconcentration, Chromatography, Derivatization, and Separation Methods

    Directory of Open Access Journals (Sweden)

    Petra Camilla Lindholm

    2014-05-01

    Full Text Available A significant portion of pharmaceuticals and other organic chemicals consumed by people and animals are released into municipal wastewater treatment plants. Most of them are degraded during the wastewater treatment processes, but some of them degrade only partially and may be widely transported and dispersed into the aquatic environment. This is why efficient and fast analytical methods are needed for detection of organic compounds in wastewaters at trace levels. Because wastewaters often consist of complex matrices and high-molecular mass materials, e.g., lignocellulosic biomass, which may bring challenges to the sample preparation procedures, efficient pre-concentration methods such as solid phase extraction (SPE solid phase microextraction (SPME, or single drop microextraction (SDME are needed. The most common analysis methods are gas chromatography (GC and liquid chromatography (LC coupled with tandem mass spectrometry (MS/MS. The aim of this review is to give an overview of chromatographic and spectroscopic methods when characterizing low- and medium-molecular weight organic pollutants, mainly focusing on pharmaceuticals, biocides, and personal care products in environmental matrices.

  20. Identification of trace levels of selenomethionine and related organic selenium species in high-ionic-strength waters.

    Science.gov (United States)

    LeBlanc, Kelly L; Ruzicka, Josef; Wallschläger, Dirk

    2016-02-01

    A new anion-exchange chromatographic separation method was used for the simultaneous speciation analysis of selenoamino acids and the more ubiquitous inorganic selenium oxyanions, selenite and selenate. For quantification, this separation was coupled to inductively coupled plasma-mass spectrometry to achieve an instrumental detection limit of 5 ng Se L(-1) for all species. This chromatographic method was also coupled to electrospray tandem mass spectrometry to observe the negative ion mode fragmentation of selenomethionine and one of its oxidation products. Low detection limits were achieved, which were similar to those obtained using inductively coupled plasma-mass spectrometry. An extensive preconcentration and cleanup procedure using cation-exchange solid-phase extraction was developed for the identification and quantification of trace levels of selenomethionine in environmental samples. Preconcentration factors of up to five were observed for selenomethionine, which in addition to the removal of high concentrations of sulphate and chloride from industrial process waters, allowed for an unambiguous analysis that would have been impossible otherwise. Following these methods, selenomethionine was identified at an original concentration of 3.2 ng Se L(-1) in samples of effluent collected at a coal-fired power plant's biological remediation site. It is the first time that this species has been identified in the environment, outside of a biological entity. Additionally, oxidation products of selenomethionine were identified in river water and laboratory algal culture samples. High-resolution mass spectrometry was employed to postulate the chemical structures of these species.

  1. Toxicity of pyrolysis gases from polyether sulfone

    Science.gov (United States)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  2. Measurements of organic gases during aerosol formation events in the boreal forest atmosphere during QUEST

    Directory of Open Access Journals (Sweden)

    K. Sellegri

    2005-01-01

    Full Text Available Biogenic VOCs are important in the growth and possibly also in the early stages of formation of atmospheric aerosol particles. In this work, we present 10 min-time resolution measurements of organic trace gases at Hyytiälä, Finland during March 2002. The measurements were part of the project QUEST (Quantification of Aerosol Nucleation in the European Boundary Layer and took place during a two-week period when nucleation events occurred with various intensities nearly every day. Using a ground-based Chemical Ionization Mass Spectrometer (CIMS instrument, the following trace gases were detected: acetone, TMA, DMA, mass 68amu (candidate=isoprene, monoterpenes, methyl vinyl ketone (MVK and methacrolein (MaCR and monoterpene oxidation products (MTOP. For all of them except for the amines, we present daily variations during different classes of nucleation events, and non-event days. BVOC oxidation products (MVK, MaCR and MTOP show a higher ratio to the CS on event days compared to non-event days, indicating that their abundance relative to the surface of aerosol available is higher on nucleation days. Moreover, BVOC oxidation products are found to show significant correlations with the condensational sink (CS on nucleation event days, which indicates that they are representative of less volatile organic compounds that contribute to the growth of the nucleated particles and generally secondary organic aerosol formation. Behaviors of BVOC on event and non event days are compared to the behavior of CO.

  3. Assessing the impact on global climate from general anesthetic gases

    DEFF Research Database (Denmark)

    Andersen, Mads P. Sulbæk; Nielsen, Ole John; Wallington, Timothy J.

    2012-01-01

    anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750). The family of anesthetic gases includes several halogenated organic compounds that are strong greenhouse gases. In this short report, we provide an overview of the state of knowledge...

  4. Selective noble gases monitoring

    International Nuclear Information System (INIS)

    Janecka, S.; Jancik, O.; Kapisovsky, V.; Kubik, I.; Sevecka, S.

    1995-01-01

    The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: 88 Kr(67; 22) Bq/m 3 ; 85m Kr(17; 7) Bq/m 3 ; 135m Xe(7.1; 0.5) Bq/m 3 ; 138 Xe(5.9; 0.9) Bq/m 3 . (J.K.)

  5. Selective noble gases monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Janecka, S; Jancik, O; Kapisovsky, V; Kubik, I; Sevecka, S [Nuclear Power Plants Research Institute, a.s., Trnava (Slovakia)

    1996-12-31

    The monitoring of leak releases from ventilation stack of NPP requires a system by several orders more sensitive then currently used radiometer Kalina, designed to cover the range up to a design-based accident. To reach this goal a noble gases monitor with a germanium detector (MPVG) has been developed. It enables nuclide selective monitoring of current value of volume activity of particular nuclides in ventilation stack and daily releases of noble gases (balancing). MPVG can be viewed as a system build of three levels of subsystem: measuring level; control level; presentation level. Measuring level consists of gamma-spectroscopy system and operational parameters monitoring unit (flow rate, temperature, humidity). Control level provides communication between presentation and measuring level, acquisition of operational parameters and power supply. The presentation level of MPVG enables: 1) the measured data storage in predetermined time intervals; 2) the presentation of measured and evaluated values of radiation characteristics. The monitored radionuclides - default set: argon-41, krypton-85m, krypton-87, krypton-88, krypton-89, xenon-131m, xenon-133, xenon-133m, xenon-135, xenon-135m, xenon-137 and xenon-138. The values of volume activities observed at maximum releases have been approximately ten times higher. In that case in balancing some other nuclides exceed corresponding detection limits: {sup 88}Kr(67; 22) Bq/m{sup 3}; {sup 85m}Kr(17; 7) Bq/m{sup 3}; {sup 135m}Xe(7.1; 0.5) Bq/m{sup 3}; {sup 138}Xe(5.9; 0.9) Bq/m{sup 3}. (J.K.).

  6. Stable isotope measurement techniques for atmospheric greenhouse gases

    International Nuclear Information System (INIS)

    2002-01-01

    The technical requirements to perform useful measurements of atmospheric greenhouse gas concentrations and of their isotope ratios are of direct relevance for all laboratories engaged in this field. A meaningful interpretation of isotopes in global models on sources and sinks of CO 2 and other greenhouse gases depends on strict laboratory protocols and data quality control measures ensuring comparable data in time and space. Only with this precondition met, the isotope techniques can serve as a potentially powerful method for reducing uncertainties in the global CO 2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. This publication provides four contributions describing methods for the determination of the isotopic composition of trace gases in atmospheric air and in ice cores. These contributions have been indexed separately

  7. Trace spaces

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth; Goubault, Eric; Haucourt, Emmanuel

    2012-01-01

    in the interleaving semantics of a concurrent program, but rather some equivalence classes. The purpose of this paper is to describe a new algorithm to compute such equivalence classes, and a representative per class, which is based on ideas originating in algebraic topology. We introduce a geometric semantics...... of concurrent languages, where programs are interpreted as directed topological spaces, and study its properties in order to devise an algorithm for computing dihomotopy classes of execution paths. In particular, our algorithm is able to compute a control-flow graph for concurrent programs, possibly containing...... loops, which is “as reduced as possible” in the sense that it generates traces modulo equivalence. A preliminary implementation was achieved, showing promising results towards efficient methods to analyze concurrent programs, with very promising results compared to partial-order reduction techniques....

  8. Greenhouse gases study in Amazonia

    International Nuclear Information System (INIS)

    D'Amelio, Monica Tais Siqueira

    2006-01-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO 2 sources. The Amazon forest is a significant source of N 2 O by soil process, and CH 4 by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO 2 , CH 4 , CO, H 2 , N 2 O and SF 6 have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO 2 flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO 2 flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H 2 gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO 2 sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that, in the 2004 and 2005 wet seasons and 2004 dry season comparison it was

  9. Stefan-Maxwell Relations and Heat Flux with Anisotropic Transport Coefficients for Ionized Gases in a Magnetic Field with Application to the Problem of Ambipolar Diffusion

    Science.gov (United States)

    Kolesnichenko, A. V.; Marov, M. Ya.

    2018-01-01

    The defining relations for the thermodynamic diffusion and heat fluxes in a multicomponent, partially ionized gas mixture in an external electromagnetic field have been obtained by the methods of the kinetic theory. Generalized Stefan-Maxwell relations and algebraic equations for anisotropic transport coefficients (the multicomponent diffusion, thermal diffusion, electric and thermoelectric conductivity coefficients as well as the thermal diffusion ratios) associated with diffusion-thermal processes have been derived. The defining second-order equations are derived by the Chapman-Enskog procedure using Sonine polynomial expansions. The modified Stefan-Maxwell relations are used for the description of ambipolar diffusion in the Earth's ionospheric plasma (in the F region) composed of electrons, ions of many species, and neutral particles in a strong electromagnetic field.

  10. Canonical partition functions: ideal quantum gases, interacting classical gases, and interacting quantum gases

    Science.gov (United States)

    Zhou, Chi-Chun; Dai, Wu-Sheng

    2018-02-01

    In statistical mechanics, for a system with a fixed number of particles, e.g. a finite-size system, strictly speaking, the thermodynamic quantity needs to be calculated in the canonical ensemble. Nevertheless, the calculation of the canonical partition function is difficult. In this paper, based on the mathematical theory of the symmetric function, we suggest a method for the calculation of the canonical partition function of ideal quantum gases, including ideal Bose, Fermi, and Gentile gases. Moreover, we express the canonical partition functions of interacting classical and quantum gases given by the classical and quantum cluster expansion methods in terms of the Bell polynomial in mathematics. The virial coefficients of ideal Bose, Fermi, and Gentile gases are calculated from the exact canonical partition function. The virial coefficients of interacting classical and quantum gases are calculated from the canonical partition function by using the expansion of the Bell polynomial, rather than calculated from the grand canonical potential.

  11. Tracing trade-related telecouplings in the global land-system using the embodied human appropriation of net primary production framework

    Science.gov (United States)

    Haberl, H.; Kastner, T.; Schaffartzik, A.; Erb, K. H.

    2015-12-01

    Global land-system change is influenced by a complex set of drivers that transcend spatial, institutional and temporal scales. The notion of "telecouplings" is gaining importance in Land System Science as a framework to address that complexity of drivers. One of them is the trade in land-based products, which forges connections between different geographic regions. Trade in land-based products is growing rapidly, thereby creating an increasing spatial disconnect between the locations where primary products (e.g. crops, fodder or timber) are grown and harvested and where the related environmental pressures occur, and the locations where final products (e.g. food, fiber or bioenergy) are consumed. Governing land-related sustainability issues such as GHG emissions or pressures on biodiversity and ecosystems related with land-use changes requires information on trade-related telecouplings, e.g. in order to avoid leakage effects. However, tracing land use (change) related with flows of traded products is challenging, among others due to (a) the lack of easily implementable metrics to account for differences in land quality and land-use intensity, and (b) the lack of satisfactory methods to allocate land to products that are traded and consumed. Drawing from a database derived from FAO statistics that allows tracing bilateral trade flows between ~200 countries at a resolution of ~500 products for the time period 1986-2006, this presentation will discuss how the framework of embodied human appropriation of net primary production (eHANPP) can help tackling these difficult issues. The HANPP framework allows to consistently represent important aspects of land quality and land-use intensity, e.g. natural productivity potential or land-use efficiency. In terms of allocation of land to products, eHANPP is a factor-based approach, and the presentation will discuss differences to alternative methods such as environmentally extended input-output analysis. We will use the available

  12. Economic Hazardous Gases Management for SOX Removal from Flue Gases

    International Nuclear Information System (INIS)

    Isaack, S.L.; Mohi, M.A.; Mohamed, S.T.

    1995-01-01

    Hazardous gases emerging from industries accumulate as pollutants in air and falls as acid rains resulting also in water and soil pollution. To minimize environmental pollution, the present process is suggested in order to desulfurize flue gases resulting from burning fuel oil in a 100/MWh steam power plant. The process makes use of the cheap Ca C O 3 powder as the alkaline material to sequistre the sulphur oxide gases. The resulting sulphur compounds, namely calcium sulphate and gypsum have a great market demand as reducing and sulphiting agents in paper industry and as an important building material. About 44000 ton of gypsum could be produced yearly when treating flue gases resulting from a 100 MWh unit burning fuel oil. Feasibility study shows that a great return on investment could be achieved when applying the process. 1 fig

  13. Avalanches in insulating gases

    International Nuclear Information System (INIS)

    Verhaart, H.F.A.

    1982-01-01

    Avalanches of charged particles in gases are often studied with the ''electrical method'', the measurement of the waveform of the current in the external circuit. In this thesis a substantial improvement of the time resolution of the measuring setup, to be used for the electrical method, is reported. The avalanche is started by an N 2 -laser with a pulse duration of only 0.6 ns. With this laser it is possible to release a high number of primary electrons (some 10 8 ) which makes it possible to obtain sizeable signals, even at low E/p values. With the setup it is possible to analyze current waveforms with a time resolution down to 1.4 ns, determined by both the laser and the measuring system. Furthermore it is possible to distinguish between the current caused by the electrons and the current caused by the ions in the avalanche and to monitor these currents simultaneously. Avalanche currents are measured in N 2 , CO 2 , O 2 , H 2 O, air of varying humidity, SF 6 and SF 6 /N 2 mixtures. Depending on the nature of the gas and the experimental conditions, processes as diffusion, ionization, attachment, detachment, conversion and secondary emission are observed. Values of parameters with which these processes can be described, are derived from an analysis of the current waveforms. For this analysis already published theories and new theories described in this thesis are used. The drift velocity of both the electrons and the ions could be easily determined from measured avalanche currents. Special attention is paid to avalanches in air becasue of the practical importance of air insulation. (Auth.)

  14. Noble gases solubility in water

    International Nuclear Information System (INIS)

    Crovetto, Rosa; Fernandez Prini, Roberto.

    1980-07-01

    The available experimental data of solubility of noble gases in water for temperatures smaller than 330 0 C have been critically surveyed. Due to the unique structure of the solvent, the solubility of noble gases in water decreases with temperature passing through a temperature of minimum solubility which is different for each gas, and then increases at higher temperatures. As aresult of the analysis of the experimental data and of the features of the solute-solvent interaction, a generalized equation is proposed which enables thecalculation of Henry's coefficient at different temperatures for all noble gases. (author) [es

  15. Meta analysis on impacts of biochar on trace greenhouse gases emissions from staple crops in China%Meta分析生物质炭对中国主粮作物痕量温室气体排放的影响

    Institute of Scientific and Technical Information of China (English)

    赵红; 孙滨峰; 逯非; 王效科; 张国; 王海勇; 张利钧; 张梦汝

    2017-01-01

    Biochar inputs have important impliations for agricultural soils, also have a significant influence on greenhouse gas emissions. This paper conducted a meta-analysis to quantitatively synthesize influence of biochar inputs on trace greenhouse gases from staple crops in China, and explored available mitigation method. The data were collected from published papers before December, 2016. The effective data were selected from the literatures including: 1) both treatments with and without biochar input; 2) methane and nitrous oxide emissions; 3) field experiment; 4) greenhouse gases from rice planting to maturity;5) reliable measurements; 6) clear and reliable yield data; 7) wheat, rice and maize in China. A total of 134 datasets were obtained. They were classified by rice paddy field and dry land, rotary tillage and plowing tillage, different biochar amount and biochar types. The response ratio was calculated with the biochar input as the treatment and no biochar input as the control. The global warming potential and the greenhouse gas intensity were calculated. The results showed that the biochar input averagely decreased the global warming potential by 18% compared with no biochar input. The global warming potential decrease by inputting biochar in the dry land was significantly higher than that in the paddy field (P<0.01). The reduction in global warming potential by inputting less than 10 t/hm2 biochar was higher than that by inputting the biochar higher than 10 t/hm2. Plowing tillage could significantly reduce the GWP by 19%. The rate of change in GWP was highest in the other biochar (41%), followed by maize biochar (20%) and wheat biochar (13%). The biochar input didn't greatly affect the methane emission in paddy field. However, the rotary tillage could significantly increase the methane emission by 30% and the inputting biochar without N application also greatly increase the methane emission. The biochar input average decreased the nitric oxides by 41% for the

  16. Changes in growth rate and macroelement and trace element accumulation in Hydrocharis morsus-ranae L. during the growing season in relation to environmental contamination.

    Science.gov (United States)

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra; Dambiec, Małgorzata

    2017-02-01

    The temporal variations in plant chemistry connected with its life cycle may affect the cycling of elements in an ecosystem as well as determine the usefulness of the species in phytoremediation and bioindication. In this context, there is a gap in knowledge on the role of floating plants for elements cycling in aquatic reservoirs. The aim of the study was to determine if there are variations in Hydrocharis morsus-ranae (European frog-bit) bioaccumulation capacity and the growth rate of its population during the growing season and to test the impact of environmental pollution on these features. The content of macroelements (Ca, K, Mg, N, Na, P, S) and trace metals (Cd, Co, Cu, Cr, Hg, Fe, Mn, Ni, Pb, Zn) was determined in H. morsus-ranae collected monthly from June to October from habitats differing in environmental contamination. The results showed that the highest content of most trace metals (Co, Cr, Cu, Hg, Mn, Ni, Zn) and some nutrients (N, P) in plants as well as the greatest bioaccumulation efficiency occurred simultaneously in the beginning of the growing season. In the following months, a dilution effect (manifested by a decrease in content) related to the rapid growth was observed. Co, Mn, and Ni content in plant tissues reflected the level of environmental contamination throughout the growing season which makes H. morsus-ranae a potential biomonitor of pollution for these metals. Considering the great bioaccumulation ability, high sensitivity to contamination, and low biomass of European frog-bit in polluted systems, further investigation is required to assess the real phytoremediation capability of the species.

  17. A nebula of gases from Io surrounding Jupiter.

    Science.gov (United States)

    Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

    2002-02-28

    Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii.

  18. Relations between variously available fractions of trace metals in the soil and their actual plant-uptake

    International Nuclear Information System (INIS)

    Bujtas, K.; Csillag, J.

    1999-01-01

    In a pot experiment, availabilities of Cd, Cr, Ni, Pb, and Zn added to the soil as metal nitrates or as enrichment of sewage sludge were evaluated by comparing concentrations of their total potentially available, presumably plant-available and directly plant-available forms in the soil. At excessively increasing soil contamination, the plant-available concentrations increased more than the total soil contents, thus the relative availabilities of the metals increased. This was reflected in the amounts taken up by the young maize test plants and in the plant/soil transfer factors. Transfer factors calculated for the 'plant-available' soil metal contents depended less on the contamination level than those based on total soil metal contents. Refs. 8 (author)

  19. Evaluation of the performance and limitations of empirical partition-relations and process based multisurface models to predict trace element solubility in soils

    Energy Technology Data Exchange (ETDEWEB)

    Groenenberg, J.E.; Bonten, L.T.C. [Alterra, Wageningen UR, P.O. Box 47, 6700 AA Wageningen (Netherlands); Dijkstra, J.J. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG Petten (Netherlands); De Vries, W. [Department of Environmental Systems Analysis, Wageningen University, Wageningen UR, P.O. Box 47, 6700 AA Wageningen (Netherlands); Comans, R.N.J. [Department of Soil Quality, Wageningen University, Wageningen UR, P.O. Box 47, 6700 AA Wageningen (Netherlands)

    2012-07-15

    Here we evaluate the performance and limitations of two frequently used model-types to predict trace element solubility in soils: regression based 'partition-relations' and thermodynamically based 'multisurface models', for a large set of elements. For this purpose partition-relations were derived for As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, Se, V, Zn. The multi-surface model included aqueous speciation, mineral equilibria, sorption to organic matter, Fe/Al-(hydr)oxides and clay. Both approaches were evaluated by their application to independent data for a wide variety of conditions. We conclude that Freundlich-based partition-relations are robust predictors for most cations and can be used for independent soils, but within the environmental conditions of the data used for their derivation. The multisurface model is shown to be able to successfully predict solution concentrations over a wide range of conditions. Predicted trends for oxy-anions agree well for both approaches but with larger (random) deviations than for cations.

  20. Trace-element measurements in atmospheric biomonitors--A look at the relative performance of INAA and PIXE on olive-tree bark

    International Nuclear Information System (INIS)

    Pacheco, Adriano M.G.; Freitas, Maria do Carmo; Reis, Miguel A.

    2003-01-01

    As part of an ongoing evaluation of its suitability for atmospheric biomonitoring, bark from olive trees (Olea europaea Linn.) has been collected and searched for trace elements by means of two nuclear-analytical techniques--instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE). The sampling for the present study was carried out across two separate sections of an established grid for air-quality surveys in mainland Portugal. The dual location comprises 58 collection sites--littoral-north (29 sites) and littoral-centre (29 sites). Both techniques are intrinsically accurate and may be seen to complement each other in the way that, as a whole, they yield 46 elements, with an overlap of 16 elements. Among the latter, this paper focuses on four of them and looks into their joint determination. Descriptive statistics for soil-related Al and Ti, and for sea-related Cl and Br, show results for each element to be fairly comparable. The degree of association between elemental patterns by either technique, as seen through nonparametric tests (Kendall's R K ), is outstanding. No statistical evidence (Wilcoxon's T) for relative bias in correlated samples--consistently higher or lower results by one technique--could be found as well. As far as this study goes, INAA and PIXE may be used interchangeably for determining the present elements in olive-tree bark

  1. Articulated Multimedia Physics, Lesson 14, Gases, The Gas Laws, and Absolute Temperature.

    Science.gov (United States)

    New York Inst. of Tech., Old Westbury.

    As the fourteenth lesson of the Articulated Multimedia Physics Course, instructional materials are presented in this study guide with relation to gases, gas laws, and absolute temperature. The topics are concerned with the kinetic theory of gases, thermometric scales, Charles' law, ideal gases, Boyle's law, absolute zero, and gas pressures. The…

  2. On Trace Zero Matrices

    Indian Academy of Sciences (India)

    In this note, we shall try to present an elemen- tary proof of a couple of closely related results which have both proved quite useful, and al~ indicate possible generalisations. The results we have in mind are the following facts: (a) A complex n x n matrix A has trace 0 if and only if it is expressible in the form A = PQ - Q P.

  3. Comparing greenhouse gases for policy purposes

    International Nuclear Information System (INIS)

    Schmalensee, R.

    1993-01-01

    In order to derive optimal policies for greenhouse gas emissions control, the discounted marginal damages of emissions from different gases must be compared. The greenhouse warming potential (GWP) index, which is most often used to compare greenhouse gases, is not based on such a damage comparison. This essay presents assumptions under which ratios of gas-specific discounted marginal damages reduce to ratios of discounted marginal contributions to radiative forcing, where the discount rate is the difference between the discount rate relevant to climate-related damages and the rate of growth of marginal climate-related damages over time. If there are important gas-specific costs or benefits not tied to radiative forcing, however, such as direct effects of carbon dioxide on plant growth, there is in general no shortcut around explicit comparison of discounted net marginal damages. 16 refs

  4. Dynamic Sampling of Trace Contaminants During the Mission Operations Test of the Deep Space Habitat

    Science.gov (United States)

    Monje, Oscar; Valling, Simo; Cornish, Jim

    2013-01-01

    The atmospheric composition inside spacecraft during long duration space missions is dynamic due to changes in the living and working environment of crew members, crew metabolism and payload operations. A portable FTIR gas analyzer was used to monitor the atmospheric composition within the Deep Space Habitat (DSH) during the Mission Operations Test (MOT) conducted at the Johnson Space Center (JSC). The FTIR monitored up to 20 gases in near- real time. The procedures developed for operating the FTIR were successful and data was collected with the FTIR at 5 minute intervals. Not all the 20 gases sampled were detected in all the modules and it was possible to measure dynamic changes in trace contaminant concentrations that were related to crew activities involving exercise and meal preparation.

  5. Quotation systems for greenhouse gases

    International Nuclear Information System (INIS)

    Trong, Maj Dang

    2000-01-01

    The article surveys recommendations from a Norwegian committee for implementing at a national level, the Kyoto protocol aims for reducing the total emissions of greenhouse gases from the industrial countries through quotation systems

  6. Photoacoustic Techniques for Trace Gas Sensing Based on Semiconductor Laser Sources

    Directory of Open Access Journals (Sweden)

    Vincenzo Spagnolo

    2009-12-01

    Full Text Available The paper provides an overview on the use of photoacoustic sensors based on semiconductor laser sources for the detection of trace gases. We review the results obtained using standard, differential and quartz enhanced photoacoustic techniques.

  7. Ultra-trace Measurements in the WAIS Divide 06A Ice Core, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — These data contain the results of gas chromatography mass spectrometry (GC-MS) analysis of 207 samples from the WAIS Divide 06A ice core. The trace gases found in...

  8. Paschen's law studies in cold gases

    OpenAIRE

    Massarczyk, R.; Chu, P.; Elliott, S. R.; Rielage, K.; Dugger, C.; Xu, W.

    2016-01-01

    The break-through voltage over small gaps has been investigated for differing gap distances, gas pressures, and gas temperatures in nitrogen, neon, argon and xenon gases. A deviation from Paschen's law at micro gap distances has been found. The breakthrough behavior of the fill gas in colder environments was tested as well. A significant shift of the curve relative to the results at room temperature was observed. The results can be explained by combining Paschen's law and the ideal gas law.

  9. Paschen's law studies in cold gases

    Science.gov (United States)

    Massarczyk, R.; Chu, P.; Dugger, C.; Elliott, S. R.; Rielage, K.; Xu, W.

    2017-06-01

    The break-through voltage behavior over small gaps has been investigated for differing gap distances, gas pressures, and gas temperatures in nitrogen, neon, argon and xenon gases. A deviation from Paschen's law at micro gap distances has been found. At lower temperatures, a significant shift of the curve relative to the results at room temperature was observed. This behavior can be explained by combining Paschen's law and the ideal gas law.

  10. Paschen's law studies in cold gases

    International Nuclear Information System (INIS)

    Massarczyk, R.; Chu, P.; Elliott, S.R.; Rielage, K.; Xu, W.; Dugger, C.

    2017-01-01

    The break-through voltage behavior over small gaps has been investigated for differing gap distances, gas pressures, and gas temperatures in nitrogen, neon, argon and xenon gases. A deviation from Paschen's law at micro gap distances has been found. At lower temperatures, a significant shift of the curve relative to the results at room temperature was observed. This behavior can be explained by combining Paschen's law and the ideal gas law.

  11. Planck intermediate results. XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust

    Science.gov (United States)

    Planck Collaboration; Adam, R.; Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.; Arnaud, M.; Arzoumanian, D.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bracco, A.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Ferrière, K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Guillet, V.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Natoli, P.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oppermann, N.; Oxborrow, C. A.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Soler, J. D.; Spencer, L. D.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Wiesemeyer, H.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-02-01

    first statistical study of the relative orientation between the matter structures and the magnetic field in the ISM points out that, at the angular scales probed by Planck, the field geometry projected on the plane of the sky is correlated with the distribution of matter. In the diffuse ISM, the structures of matter are usually aligned with the magnetic field, while perpendicular structures appear in molecular clouds. We discuss our results in the context of models and MHD simulations, which attempt to describe the respective roles of turbulence, magnetic field, and self-gravity in the formation of structures in the magnetized ISM.

  12. Planck intermediate results: XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust

    International Nuclear Information System (INIS)

    Adam, R.; Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.; Arnaud, M.

    2016-01-01

    projection effects. This first statistical study of the relative orientation between the matter structures and the magnetic field in the ISM points out that, at the angular scales probed by Planck, the field geometry projected on the plane of the sky is correlated with the distribution of matter. In the diffuse ISM, the structures of matter are usually aligned with the magnetic field, while perpendicular structures appear in molecular clouds. Finally, we discuss our results in the context of models and MHD simulations, which attempt to describe the respective roles of turbulence, magnetic field, and self-gravity in the formation of structures in the magnetized ISM.

  13. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    Reynolds, J.H.

    1988-08-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  14. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    1987-07-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  15. Trace metal emissions from the Estonian oil shale fired power

    DEFF Research Database (Denmark)

    Aunela-Tapola, Leena A.; Frandsen, Flemming; Häsänen, Erkki K.

    1998-01-01

    Emission levels of selected trace metals from the Estonian oil shale fired power plant were studied. The plant is the largest single power plant in Estonia with an electricity production capacity of 1170 MWe (1995). Trace metals were sampled from the flue gases by a manual method incorporating...... in the flue gases of the studied oil shale plant contribute, however, to clearly higher total trace metal emission levels compared to modern coal fired power plants. Although the old electrostatic precipitators in the plant have been partly replaced by state-of-the-art electrostatic precipitators...... a two-fraction particle sampling and subsequent absorption of the gaseous fraction. The analyses were principally performed with ICP-MS techniques. The trace metal contents of Estonian oil shale were found to be in the same order of magnitude as of coal on average. The high total particle concentrations...

  16. Trace formulae for arithmetical systems

    International Nuclear Information System (INIS)

    Bogomolny, E.B.; Georgeot, B.; Giannoni, M.J.; Schmit, C.

    1992-09-01

    For quantum problems on the pseudo-sphere generated by arithmetic groups there exist special trace formulae, called trace formulae for Hecke operators, which permit the reconstruction of wave functions from the knowledge of periodic orbits. After a short discussion of this subject, the Hecke operators trace formulae are presented for the Dirichlet problem on the modular billiard, which is a prototype of arithmetical systems. The results of numerical computations for these semiclassical type relations are in good agreement with the directly computed eigenfunctions. (author) 23 refs.; 2 figs

  17. Occurrence, emission and ignition of combustible strata gases in Witwatersrand gold mines and Bushveld platinum mines, and means of ameliorating related ignition and explosion hazards, Part 1: literature and technical review.

    CSIR Research Space (South Africa)

    Cook, AP

    1998-10-01

    Full Text Available 60 62 63 64 9 Terminology and abbreviations The terms combustible, flammable and inflammable, to describe gases encountered in mining, are all used commonly in literature and within the South African mining industry. The Concise Oxford English... dictionary defines them as: combustible: capable of burning inflammable: easily set on fire flammable: rarely used except in “nonflammable”. In this report combustible and flammable are used to describe gas or gases that will burn or explode in air...

  18. Properties of quantum self-gravitating gases

    International Nuclear Information System (INIS)

    Rumyantseva, E.N.

    1981-01-01

    Ways of development of the quantum field theory in the general relativity theory are under consideration. A direction, where consideration of quantum fields in strong nonstatic gravitational fields leads to such effects as particle production, is found out. Authors managed to explain properties of quantum self-gravitating gases on the base of an expansion the fugacity in power series for bose- and fermi gases. Expressions for fluctuations in statistical models of the Fridmann universe are presented. The spectrum density of relict neutrinos in Fridmann models is calculated. A characteristic low boundary of the neutrino energy spectrum constitutes 1 MeV. A number of neutrinos with such energies practically is equal to zero. A great number of neutrinos has energies 0 . It is precisely these neurinos, which are responsible for the closed state of the universe according to the built up model

  19. Radioactive gases monitor system: tritium, radon, noble gases

    International Nuclear Information System (INIS)

    Egey, J.Z.; Matatagui, E.

    2015-01-01

    A system for monitoring the radioactive gases tritium, radon and noble gases is described. We present the description of the sensor and the associated electronics that have been developed to monitor the presence of radioactive gases in air or other gaseous effluents. The system has a high sensitivity and a wide range of operation. The sensor is an ionization chamber, featuring the internal circulation of the gas to monitor and the associated electronics has a resolution better than 10 E-15A (fA). It allows the detection of the individual pulses that are produced during the alpha decay of radon and its daughter elements. The measurement system is made up of a commercial data acquisition system connected to a computer. The acquired data is presented on a graphical display and it is stored for later processing and analysis. We have a system that is of simple construction and versatile. Here we present the experimental results. (authors) [es

  20. Gases and carbon in metals

    International Nuclear Information System (INIS)

    Jehn, H.; Fromm, E.; Hoerz, G.

    1978-01-01

    This issue is part of a series of data on 'gases and carbon in metals'. The present survey includes results from papers dealing with gases and carbon in actinides and recommends critically selected data for each element. Firstly data od binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility limit, dissociation pressure of compunds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas adsorption and gas desorption kinetics, compound formation, precipitation kinetics, and property changes. Following the data on binary systems, the data of ternary systems are presented, beginning with systems which contain one metal and two gases or one gas and carbon and continuing with systems with two metals and one gas or carbon. Within a ternary system the topics are arranged in the same way as in binary systems. (HB) [de

  1. Epidemic contact tracing via communication traces.

    Directory of Open Access Journals (Sweden)

    Katayoun Farrahi

    Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  2. Epidemic contact tracing via communication traces.

    Science.gov (United States)

    Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel

    2014-01-01

    Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  3. History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE

    Directory of Open Access Journals (Sweden)

    R. G. Prinn

    2018-06-01

    to determine the average concentrations and trends of tropospheric hydroxyl radicals (OH from the rates of destruction of atmospheric trichloroethane (CH3CCl3, HFCs, and HCFCs and estimates of their emissions; (5 to determine from atmospheric observations and estimates of their destruction rates the magnitudes and distributions by region of surface sources and sinks of all measured gases; (6 to provide accurate data on the global accumulation of many of these trace gases that are used to test the synoptic-, regional-, and global-scale circulations predicted by three-dimensional models; and (7 to provide global and regional measurements of methane, carbon monoxide, and molecular hydrogen and estimates of hydroxyl levels to test primary atmospheric oxidation pathways at midlatitudes and the tropics. Network Information and Data Repository: http://agage.mit.edu/data or http://cdiac.ess-dive.lbl.gov/ndps/alegage.html (https://doi.org/10.3334/CDIAC/atg.db1001.

  4. Desulphurization of exhaust gases in chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1981-01-01

    The sulfur content of exhaust gases can be reduced by: desulphurization of fuels; modification of processes; or treatment of resultant gases. In this paper a few selected examples from the chemical industry in the German Democratic Republic are presented. Using modified processes and treating the resultant gases, the sulphuric content of exhaust gases is effectively reduced. Methods to reduce the sulfur content of exhaust gases are described in the field of production of: sulphuric acid; viscose; fertilizers; and paraffin.

  5. The dopamine D1 receptor agonist SKF81297 has dose-related effects on locomotor activity but is without effect in a CER trace conditioning procedure conducted with two versus four trials.

    Science.gov (United States)

    Pezze, M A; Marshall, H J; Cassaday, H J

    2016-08-01

    In an appetitively motivated procedure, we have previously reported that systemic treatment with the dopamine (DA) D1 receptor agonist SKF81297 (0.4 and 0.8 mg/kg) depressed acquisition at a 2 s inter-stimulus-interval (ISI), suitable to detect trace conditioning impairment. However since DA is involved in reinforcement processes, the generality of effects across appetitively- and aversively-motivated trace conditioning procedures cannot be assumed. The present study tested the effects of SKF81297 (0.4 and 0.8 mg/kg) in an established conditioned emotional response (CER) procedure. Trace-dependent conditioning was clearly shown in two experiments: while conditioning was relatively strong at a 3-s ISI, it was attenuated at a 30-s ISI. This was shown after two (Experiment 1) or four (Experiment 2) conditioning trials conducted in - as far as possible - the same CER procedure. Contrary to prediction, in neither experiment was there any indication that trace conditioning was attenuated by treatment with 0.4 or 0.8 mg/kg SKF81297. In the same rats, locomotor activity was significantly enhanced at the 0.8 mg/kg dose of SKF81297. These results suggest that procedural details of the trace conditioning variant in use are an important determinant of the profile of dopaminergic modulation.

  6. Process for separating radioactive gases

    International Nuclear Information System (INIS)

    Kimura, Shigeru; Awada, Yoshihisa.

    1976-01-01

    Object: To efficiently and safely separate and recover raw gases such as krypton which requires radioactive attenuation by a long term storage. Structure: A mixture of krypton and xenon is separated by liquefaction from raw gases at a first distillation column, using latent heat of liquid nitrogen. The krypton and xenon mixture separated by liquefaction at the first distillation column is separated into krypton and xenon, by controlling operation pressure of a second distillation column at about 3 - 5 atm., using sensible heat of low temperature nitrogen gas discharged from a top of the first distillation column and a condenser. (Aizawa, K.)

  7. The ideal gases of tachyons

    International Nuclear Information System (INIS)

    Mrowczynski, St.

    1984-01-01

    The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed

  8. A microscope for Fermi gases

    International Nuclear Information System (INIS)

    Omran, Ahmed

    2016-01-01

    This thesis reports on a novel quantum gas microscope to investigate many-body systems of fermionic atoms in optical lattices. Single-site resolved imaging of ultracold lattice gases has enabled powerful studies of bosonic quantum many-body systems. The extension of this capability to Fermi gases offers new prospects to studying complex phenomena of strongly correlated systems, for which numerical simulations are often out of reach. Using standard techniques of laser cooling, optical trapping, and evaporative cooling, ultracold Fermi gases of 6 Li are prepared and loaded into a large-scale 2D optical lattice of flexible geometry. The atomic distribution is frozen using a second, short-scaled lattice, where we perform Raman sideband cooling to induce fluorescence on each atom while maintaining its position. Together with high-resolution imaging, the fluorescence signals allow for reconstructing the initial atom distribution with single-site sensitivity and high fidelity. Magnetically driven evaporative cooling in the plane allows for producing degenerate Fermi gases with almost unity filling in the initial lattice, allowing for the first microscopic studies of ultracold gases with clear signatures of Fermi statistics. By preparing an ensemble of spin-polarised Fermi gases, we detect a flattening of the density profile towards the centre of the cloud, which is a characteristic of a band-insulating state. In one set of experiments, we demonstrate that losses of atom pairs on a single lattice site due to light-assisted collisions are circumvented. The oversampling of the second lattice allows for deterministic separation of the atom pairs into different sites. Compressing a high-density sample in a trap before loading into the lattice leads to many double occupancies of atoms populating different bands, which we can image with no evidence for pairwise losses. We therefore gain direct access to the true number statistics on each lattice site. Using this feature, we can

  9. Quantum gases finite temperature and non-equilibrium dynamics

    CERN Document Server

    Szymanska, Marzena; Davis, Matthew; Gardiner, Simon

    2013-01-01

    The 1995 observation of Bose-Einstein condensation in dilute atomic vapours spawned the field of ultracold, degenerate quantum gases. Unprecedented developments in experimental design and precision control have led to quantum gases becoming the preferred playground for designer quantum many-body systems. This self-contained volume provides a broad overview of the principal theoretical techniques applied to non-equilibrium and finite temperature quantum gases. Covering Bose-Einstein condensates, degenerate Fermi gases, and the more recently realised exciton-polariton condensates, it fills a gap by linking between different methods with origins in condensed matter physics, quantum field theory, quantum optics, atomic physics, and statistical mechanics. Thematically organised chapters on different methodologies, contributed by key researchers using a unified notation, provide the first integrated view of the relative merits of individual approaches, aided by pertinent introductory chapters and the guidance of ed...

  10. Laser-aided diagnostics of plasmas and gases

    CERN Document Server

    Muraoka, K

    2000-01-01

    Updated and expanded from the original Japanese edition, Laser-Aided Diagnostics of Gases and Plasmas takes a unique approach in treating laser-aided diagnostics. The book unifies the subject by joining applications instead of describing each application as a totally separate system. In taking this approach, it highlights the relative strengths of each method and shows how they can complement each other in the study of gases and plasmas.The first part of the book presents a general introduction to the laser-aided study of gases and plasmas, including the various principles and hardware needed for each method, while the second part describes the applications of each general system in detail.Beneficial to a wide spectrum of academic and industrial researchers, this book provides a solid examination of the various options and methods available when involved in the analysis and diagnostics of gases and plasmas.

  11. Dipolar quantum gases of erbium

    International Nuclear Information System (INIS)

    Frisch, A.

    2014-01-01

    Since the preparation of the first Bose-Einstein condensate about two decades ago and the first degenerate Fermi gas following four years later a plethora of fascinating quantum phenomena have been explored. The vast majority of experiments focused on quantum degenerate atomic gases with short-range contact interaction between particles. Atomic species with large magnetic dipole moments, such as chromium, dysprosium, and erbium, offer unique possibilities to investigate phenomena arising from dipolar interaction. This kind of interaction is not only long-range but also anisotropic in character and imprints qualitatively novel features on the system. Prominent examples are the d-wave collapse of a dipolar Bose-Einstein condensate of chromium atoms realized by the group in Stuttgart, the spin magnetization and demagnetization dynamics observed by groups in Stuttgart, Paris, and Stanford, and the deformation of the Fermi surface observed by our group in Innsbruck. This thesis reports on the creation and study of the first Bose-Einstein condensate and degenerate Fermi gas of erbium atoms. Erbium belongs to the lanthanide group of elements and has a large magnetic moment of seven Bohr magneton. In particular, this thesis describes the experimental apparatus and the sequence for producing a dipolar quantum gas. There is an emphasis on the production of the narrow-line magneto-optical trap of erbium since this represents a very efficient and robust laser-cooling scheme that greatly simplifies the experimental procedure. After describing the experimental setup this thesis focuses on several fundamental questions related to the dipolar character of erbium and to its lanthanide nature. A first set of studies centers on the scattering properties of ultracold erbium atoms, including the elastic and the inelastic cross section and the spectrum of Feshbach resonances. Specifically, we observe that identical dipolar fermions do collide and rethermalize even at low temperatures

  12. Applications of stable isotope analysis to atmospheric trace gas budgets

    Directory of Open Access Journals (Sweden)

    Brenninkmeijer C. A.M.

    2009-02-01

    Full Text Available Stable isotope analysis has become established as a useful method for tracing the budgets of atmospheric trace gases and even atmospheric oxygen. Several new developments are briefly discussed in a systematic way to give a practical guide to the scope of recent work. Emphasis is on applications and not on instrumental developments. Processes and reactions are less considered than applications to resolve trace gas budgets. Several new developments are promising and applications hitherto not considered to be possible may allow new uses.

  13. Transport processes in ionized gases

    International Nuclear Information System (INIS)

    Kremer, G.M.

    1997-01-01

    Based on kinetic theory of gases and on the combined of Chapman-Enskog and Grad, the laws of Ohm, Fourier and Navier-Stokes are derived for a non-relativistic fully ionized gas. Moreover, the combined method is applied to the BGK model of the relativistic Boltzmann equation and the Ohm's law is derived for a relativistic fully ionized gas. (author)

  14. Stratospheric aerosols and precursor gases

    Science.gov (United States)

    1982-01-01

    Measurements were made of the aerosol size, height and geographical distribution, their composition and optical properties, and their temporal variation with season and following large volcanic eruptions. Sulfur-bearing gases were measured in situ in the stratosphere, and studied of the chemical and physical processes which control gas-to-particle conversion were carried out in the laboratory.

  15. Permeability of cork to gases.

    Science.gov (United States)

    Faria, David P; Fonseca, Ana L; Pereira, Helen; Teodoro, Orlando M N D

    2011-04-27

    The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 μmol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 μmol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

  16. Tracing sediment sources in the Williams River catchment using caesium-137 and heavy metals: towards an assessment of the relative importance of surface erosion and gully erosion

    International Nuclear Information System (INIS)

    Krause, A.K.; Kalma, J.D.; Loughran, R.J.

    1999-01-01

    Recent sediment sourcing in the 1175km 2 Williams River catchment near Newcastle, NSW, has involved the use of caesium-137 ( 137 Cs) and heavy metals to identify zones of erosion and estimate erosion rates. Sediment sources to the Williams River include sheet erosion from forested and grazed lands, stream channels (especially banks), gullies and roads. The fallout environmental radioisotope 137 Cs was used to assess the erosion status of five vegetated slopes using soil sampling along transects. The net loss or gain of 137 Cs at each sampling point was compared with the 137 Cs level at a reference site at the slope crest. Net soil loss at each point was calculated from an Australian regression model relating net soil loss from runoff-erosion plots to 137 Cs deficit in soils (n=34; r=0.84). Net soil gain was calculated using the regression model in reverse mode. A weighted net soil loss (or gain) was then calculated for each slope transect. Results showed low net soil loss, ranging from zero to 0.64 t ha -1 yr 1 , suggesting that slopes were not major contributors of sediment to the Williams River. A small sub-catchment south of Wirragulla Hill, typical of the lower Williams region, was selected for more detailed tracing of sediment sources. The catchment contains gullies, sheet-erosion exposed sub-soil, grassland and one unsealed road. Heavy metals and 137 Cs have been used to fingerprint the sources, and these measurements will be compared with suspended sediment collected from drainage water in the creek. Only preliminary results have been obtained for this component of the study. The paper will assess these two approaches for the identification of sediment sources and discuss practical applications in water resources management

  17. Concurrent Use of H.sub.3./sub.O.sup.+./sup., NO.sup.+./sup., and O.sub.2./sub..sup.+./sup. Precursor Ions for the Detection and Quantification of Diverse Trace Gases in the Presence of Air and Breath by Selected Ion-Flow Tube mass Spectrometry

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Diskin, A. M.; Yufeng, Ji.; Španěl, Patrik

    2001-01-01

    Roč. 209, č. 1 (2001), s. 81-97 ISSN 1387-3806 R&D Projects: GA ČR GA203/97/P130 Institutional research plan: CEZ:AV0Z4040901 Keywords : SIFT-MS * trace-gas analysis * chemical ionization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.176, year: 2001

  18. Comparative Study of Raw and Boiled Silver Pomfret Fish from Coastal Area and Retail Market in Relation to Trace Metals and Proximate Composition

    Science.gov (United States)

    Huque, Roksana; Munshi, M. Kamruzzaman; Khatun, Afifa; Islam, Mahfuza; Hossain, Afzal; Hossain, Arzina; Akter, Shirin; Kabir, Jamiul; Nahar Jolly, Yeasmin; Islam, Ashraful

    2014-01-01

    Trace metals concentration and proximate composition of raw and boiled silver pomfret (Pampus argenteus) from coastal area and retail market were determined to gain the knowledge of the risk and benefits associated with indiscriminate consumption of marine fishes. The effects of cooking (boiling) on trace metal and proximate composition of silver pomfret fish were also investigated. Trace element results were determined by the Energy Dispersive X-ray Fluorescence (EDXRF) Spectrometer wherein fish samples from both areas exceeded the standard limits set by FAO/WHO for manganese, lead, cadmiumm and chromium and boiling has no significant effects on these three metal concentrations. Long-term intake of these contaminated fish samples can pose a health risk to humans who consume them. PMID:26904650

  19. Comparative Study of Raw and Boiled Silver Pomfret Fish from Coastal Area and Retail Market in Relation to Trace Metals and Proximate Composition

    Directory of Open Access Journals (Sweden)

    Roksana Huque

    2014-01-01

    Full Text Available Trace metals concentration and proximate composition of raw and boiled silver pomfret (Pampus argenteus from coastal area and retail market were determined to gain the knowledge of the risk and benefits associated with indiscriminate consumption of marine fishes. The effects of cooking (boiling on trace metal and proximate composition of silver pomfret fish were also investigated. Trace element results were determined by the Energy Dispersive X-ray Fluorescence (EDXRF Spectrometer wherein fish samples from both areas exceeded the standard limits set by FAO/WHO for manganese, lead, cadmiumm and chromium and boiling has no significant effects on these three metal concentrations. Long-term intake of these contaminated fish samples can pose a health risk to humans who consume them.

  20. Extraction of trapped gases in ice cores for isotope analysis

    International Nuclear Information System (INIS)

    Leuenberger, M.; Bourg, C.; Francey, R.; Wahlen, M.

    2002-01-01

    The use of ice cores for paleoclimatic investigations is discussed in terms of their application for dating, temperature indication, spatial time marker synchronization, trace gas fluxes, solar variability indication and changes in the Dole effect. The different existing techniques for the extraction of gases from ice cores are discussed. These techniques, all to be carried out under vacuum, are melt-extraction, dry-extraction methods and the sublimation technique. Advantages and disadvantages of the individual methods are listed. An extensive list of references is provided for further detailed information. (author)

  1. Separation of gases

    International Nuclear Information System (INIS)

    Wang, C.G.

    1980-01-01

    A process for separating gaseous mixtures of molecules of different mass comprises the steps of: causing a rotational nozzle to eject a contiguous plurality of successive groups of molecules into an evacuated space, the groups mutually overlapping to form a continuous stream of the mixture in the form of an Archimedean spiral, allowing the molecules of each group of molecules to move in accordance with their thermal velocities for a predetermined period of time following ejection, thereby to allow each group of molecules to form a generally spherical configuration the outer portion of which will be enriched, in molecules of lighter mass, relative to the inner portion thereof, using a deflector means co-rotating with the rotating nozzle to deflect molecules, which have been allowed to move for the predetermined period of time in accordance with their thermal velocities, from at least one desired portion of the stream and using a stationary collector means to collect the deflected molecules. The process is described with reference to the separation of isotopes of uranium hexafluoride. (author)

  2. Sensitive Multi-Species Emissions Monitoring: Infrared Laser-Based Detection of Trace-Level Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Steill, Jeffrey D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Huang, Haifeng [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hoops, Alexandra A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Patterson, Brian D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Birtola, Salvatore R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Jaska, Mark [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Strecker, Kevin E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Chandler, David W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bisson, Soott [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    This report summarizes our development of spectroscopic chemical analysis techniques and spectral modeling for trace-gas measurements of highly-regulated low-concentration species present in flue gas emissions from utility coal boilers such as HCl under conditions of high humidity. Detailed spectral modeling of the spectroscopy of HCl and other important combustion and atmospheric species such as H 2 O, CO 2 , N 2 O, NO 2 , SO 2 , and CH 4 demonstrates that IR-laser spectroscopy is a sensitive multi-component analysis strategy. Experimental measurements from techniques based on IR laser spectroscopy are presented that demonstrate sub-ppm sensitivity levels to these species. Photoacoustic infrared spectroscopy is used to detect and quantify HCl at ppm levels with extremely high signal-to-noise even under conditions of high relative humidity. Additionally, cavity ring-down IR spectroscopy is used to achieve an extremely high sensitivity to combustion trace gases in this spectral region; ppm level CH 4 is one demonstrated example. The importance of spectral resolution in the sensitivity of a trace-gas measurement is examined by spectral modeling in the mid- and near-IR, and efforts to improve measurement resolution through novel instrument development are described. While previous project reports focused on benefits and complexities of the dual-etalon cavity ring-down infrared spectrometer, here details on steps taken to implement this unique and potentially revolutionary instrument are described. This report also illustrates and critiques the general strategy of IR- laser photodetection of trace gases leading to the conclusion that mid-IR laser spectroscopy techniques provide a promising basis for further instrument development and implementation that will enable cost-effective sensitive detection of multiple key contaminant species simultaneously.

  3. Neutrino oscillations in dense neutrino gases

    International Nuclear Information System (INIS)

    Samuel, S.

    1993-01-01

    We consider oscillations of neutrinos under conditions in which the neutrino density is sufficiently large that neutrino-neutrino interactions cannot be neglected. A formalism is developed to treat this highly nonlinear system. Numerical analysis reveals a rich array of phenomena. In certain gases, a self-induced Mikheyev-Smirnov-Wolfenstein effect occurs in which electron neutrinos are resonantly converted into muon neutrinos. In another relatively low-density gas, an unexpected parametric resonant conversion takes place. Finally, neutrino-neutrino interactions maintain coherence in one system for which a priori one expected decoherence

  4. Effects of OEF/OIF-Related Physical and Emotional Co-Morbidities on Associative Learning: Concurrent Delay and Trace Eyeblink Classical Conditioning

    Directory of Open Access Journals (Sweden)

    Regina E. McGlinchey

    2014-03-01

    Full Text Available This study examined the performance of veterans and active duty personnel who served in Operation Enduring Freedom and/or Operation Iraqi Freedom (OEF/OIF on a basic associative learning task. Eighty-eight individuals participated in this study. All received a comprehensive clinical evaluation to determine the presence and severity of posttraumatic stress disorder (PTSD and traumatic brain injury (TBI. The eyeblink conditioning task was composed of randomly intermixed delay and trace conditioned stimulus (CS and unconditioned stimulus (US pairs (acquisition followed by a series of CS only trials (extinction. Results revealed that those with a clinical diagnosis of PTSD or a diagnosis of PTSD with comorbid mTBI acquired delay and trace conditioned responses (CRs to levels and at rates similar to a deployed control group, thus suggesting intact basic associative learning. Differential extinction impairment was observed in the two clinical groups. Acquisition of CRs for both delay and trace conditioning, as well as extinction of trace CRs, was associated with alcoholic behavior across all participants. These findings help characterize the learning and memory function of individuals with PTSD and mTBI from OEF/OIF and raise the alarming possibility that the use of alcohol in this group may lead to more significant cognitive dysfunction.

  5. Use of gases in dairy manufacturing: A review.

    Science.gov (United States)

    Adhikari, Bhaskar Mani; Truong, Tuyen; Bansal, Nidhi; Bhandari, Bhesh

    2017-06-13

    Use of gases (air, carbon dioxide and nitrogen) has been practiced in the manufacture of dairy products (i.e., ice cream, whipped cream and butter) to improve their texture, mouthfeel and shelf-life extension. Many attempts have also been made to incorporate other gases such as hydrogen, nitrous oxide, argon, xenon, and helium into the dairy systems for various product functionalities such as whipping, foaming, texture, aroma enhancement, and therapeutic properties. The gases can be dissolved in aqueous and fat phases or remain in the form of bubbles stabilized by protein or fat particles. The gas addition or infusion processes are typically simple and have been used commercially. This review focuses on the use of various gases in relation to their individually physical properties along with their specific roles in manufacturing and controlling quality of dairy products. It also recaps on how gases are included in the dairy systems. The information is important in understanding of addition of specific gas(es) into food systems, particularly dairy products, that potentially provide intervention opportunities for modifying and/or creating innovative food structures and functionalities.

  6. Soliton Gases and Generalized Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Yoshimura, Takato; Caux, Jean-Sébastien

    2018-01-01

    We show that the equations of generalized hydrodynamics (GHD), a hydrodynamic theory for integrable quantum systems at the Euler scale, emerge in full generality in a family of classical gases, which generalize the gas of hard rods. In this family, the particles, upon colliding, jump forward or backward by a distance that depends on their velocities, reminiscent of classical soliton scattering. This provides a "molecular dynamics" for GHD: a numerical solver which is efficient, flexible, and which applies to the presence of external force fields. GHD also describes the hydrodynamics of classical soliton gases. We identify the GHD of any quantum model with that of the gas of its solitonlike wave packets, thus providing a remarkable quantum-classical equivalence. The theory is directly applicable, for instance, to integrable quantum chains and to the Lieb-Liniger model realized in cold-atom experiments.

  7. Noble Gases in Lakes and Ground Waters

    OpenAIRE

    Kipfer, Rolf; Aeschbach-Hertig, Werner; Peeters, Frank; Stute, Marvin

    2002-01-01

    In contrast to most other fields of noble gas geochemistry that mostly regard atmospheric noble gases as 'contamination,' air-derived noble gases make up the far largest and hence most important contribution to the noble gas abundance in meteoric waters, such as lakes and ground waters. Atmospheric noble gases enter the meteoric water cycle by gas partitioning during air / water exchange with the atmosphere. In lakes and oceans noble gases are exchanged with the free atmosphere at the surface...

  8. Centrifugal separation of mixture gases

    International Nuclear Information System (INIS)

    Zhou, M.S.; Chen, W.N.; Yin, Y.T.

    2008-01-01

    An attempt for single centrifugal separation of mixtures with different molecular formula was presented in this paper. The mixtures of SF 6 and CCl 3 F, and SF 6 and CCl 4 were chosen as the processing gases, which were prepared in three mass ratios, 0.5, 0.8 and 0.2, respectively. The separating characteristics such as the overall separation factors and the variation of cuts were studied. (author)

  9. Landfill gases and some effects on vegetation

    Science.gov (United States)

    Franklin B. Flower; Ida A. Leone; Edward F. Gilman; John J. Arthur

    1977-01-01

    Gases moving from refuse landfills through soil were studied in New Jersey. The gases, products of anaerobic decomposition of organic matter in the refuse, caused injury and death of peach trees, ornamentals, and commercial farm crops, and create possible hazards to life and property because of the entrance of combustible gases into residences. Remedial measures are...

  10. Subcooled boiling effect on dissolved gases behaviour

    International Nuclear Information System (INIS)

    Zmitko, M.; Sinkule, J.; Linek, V.

    1999-01-01

    A model describing dissolved gasses (hydrogen, nitrogen) and ammonia behaviour in subcooled boiling conditions of WWERs was developed. Main objective of the study was to analyse conditions and mechanisms leading to formation of a zone with different concentration of dissolved gases, eg. a zone depleted in dissolved hydrogen in relation to the bulk of coolant. Both, an equilibrium and dynamic approaches were used to describe a depletion of the liquid surrounding a steam bubble in the gas components. The obtained results show that locally different water chemistry conditions can be met in the subcooled boiling conditions, especially, in the developed subcooled boiling regime. For example, a 70% hydrogen depletion in relation to the bulk of coolant takes about 1 ms and concerns a liquid layer of 1 μn surrounding the steam bubble. The locally different concentration of dissolved gases can influence physic-chemical and radiolytic processes in the reactor system, eg. Zr cladding corrosion, radioactivity transport and determination of the critical hydrogen concentration. (author)

  11. A pilot double-blind, randomized, placebo-controlled trial of the efficacy of trace elements in the treatment of endometriosis-related pain: study design and methodology

    Directory of Open Access Journals (Sweden)

    Oberweis D

    2016-02-01

    Full Text Available Didier Oberweis,1 Patrick Madelenat,2 Michelle Nisolle,3 Etienne Demanet4 1Department of Gynecology and Obstetrics, CHU de Charleroi, Hôpital André Vésale, Montigny-le-Tilleul, Belgium; 2Private Consultation, Paris, France; 3Department of Gynecology and Obstetrics, CHR Citadelle, Liège, 4Clinical Research Unit, Charleroi, Belgium Abstract: Endometriosis is one of the most common benign gynecological disorders, affecting almost 10%–15% of all women of reproductive age and >30% of infertile women. The pathology is associated with various distressing symptoms, particularly pelvic pain, which adversely affect patients' quality of life. It is an estrogen-dependent disease. There is evidence both in animals and in humans that metal ions can activate the estrogen receptors. They are defined as a variety of xenoestrogens, called metalloestrogens, which could act as endocrine disruptors. Therefore, it could be considered to act on this gynecological disorder using food supplements containing trace elements (ie, nutripuncture. The assumption is that they could modulate estrogen receptors and thus influence the tropism and the survival of cells involved in endometriosis. By a modulation of the antioxidant system, they might also interact with various parameters influencing tissue biochemistry. The objective of this article is to describe and discuss the design and methodology of an ongoing double-blind, randomized, placebo-controlled study aiming to evaluate the efficacy of metal trace elements on the reduction of pain and improvement of quality of life, in patients with a revised American Fertility Society Score Stages II–IV endometriosis, combined or not with adenomyosis, during a treatment period of 4 months. Trace elements or placebo is proposed in the absence of any other treatment or as an add-on to current therapies, such as sexual hormones, nonsteroidal anti-inflammatory drugs, and surgery. A placebo run-in period of one menstrual cycle or

  12. Variability of PAHs and trace metals in the sediments in relation to environmental characteristics of the bottom layer in the middle Adriatic Sea

    Science.gov (United States)

    Grilli, Federica; Frapiccini, Emanuela; Campanelli, Alessandra; Guicciardi, Stefano; Marini, Mauro; Marasovic, Ivona; Grbec, Branka; Skejić, Sanda; Ujević, Ivana; Lušić, Jelena

    2015-04-01

    In the framework of the project PERSEUS (Policy-oriented marine Environmental Research in the Southern EUropean Seas), two interdisciplinary surveys were carried out in April 2013 and April 2014 in the middle Adriatic Sea along the Pescara-Sibenik transect (Jabuka Pits area) and Vieste-Split transect (Palagruza Sill area) with Croatian research vessel "Bios II" and the Italian research vessel "G. Dallaporta", respectively. The main objective of these research cruises was the implementation of the Marine Strategy Framework Directive (MSFD) in the Adriatic region for collecting physical, chemical and biological data in order to get a better understanding of whole Adriatic ecosystem. The two transects are already recognised as a key areas for the interception and the study of dense water modification (Zore-Armanda, 1963; Marini et al., 2006; Grilli et al., 2013). Due to seasonal circulation patterns, they are characterized by high temporal variability of the thermohaline structure (Grbec and Morović, 1997; Vilibić, et al., 2004) and other oceanographic parameters. Long term oceanographic records from the Middle Adriatic enable better understanding of the ecosystem response to changes of atmospheric and sea conditions through physical, chemical and biological processes (Marasović et al., 1995). Several oceanographic parameters relevant and useful for the ecosystem assessment of the two areas (temperature, salinity, density, fluorescence, oxygen, nutrients, chlorophyll, phyto- and zoo-plankton as well as selected pollutants , trace metals and Polycyclic Aromatic Hydrocarbons-PAHs in sediments) were collected. In the present work, the variations of PAHs and trace metals concentration in the marine sediments are presented in relation to the physical and chemical characteristics of the bottom layer. A constant influx of metal induces more intense accumulation of anthropogenic metals, especially Cd, in sediment from Jabuka Pit, and the metal content slightly increases

  13. Greenhouse Gases and Animal Agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, J. (ed.) [Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido (Japan); Young, B.A. (ed.) [The University of Queensland, Gatton, Queensland 4343 (Australia)

    2002-07-01

    Reports from interdisciplinary areas including microbiology, biochemistry, animal nutrition, agricultural engineering and economics are integrated in this proceedings. The major theme of this book is environmental preservation by controlling release of undesirable greenhouse gases to realize the sustainable development of animal agriculture. Technology exists for the effective collection of methane generated from anaerobic fermentation of animal effluent and its use as a biomass energy source. Fossil fuel consumption can be reduced and there can be increased use of locally available energy sources. In addition, promoting environmentally-conscious agriculture which does not rely on the chemical fertilizer can be realized by effective use of animal manure and compost products.

  14. Mechanics of liquids and gases

    CERN Document Server

    Loitsyanskii, L G; Jones, W P

    1966-01-01

    Mechanics of Liquids and Gases, Second Edition is a 10-chapter text that covers significant revisions concerning the dynamics of an ideal gas, a viscous liquid and a viscous gas.After an expanded introduction to the fundamental properties and methods of the mechanics of fluids, this edition goes on dealing with the kinetics and general questions of dynamics. The next chapters describe the one-dimensional pipe flow of a gas with friction, the elementary theory of the shock tube; Riemann's theory of the wave propagation of finite intensity, and the theory of plane subsonic and supersonic flows.

  15. Aerodynamic features of flames in premixed gases

    Science.gov (United States)

    Oppenheim, A. K.

    1984-01-01

    A variety of experimentally established flame phenomena in premixed gases are interpreted by relating them to basic aerodynamic properties of the flow field. On this basis the essential mechanism of some well known characteristic features of flames stabilized in the wake of a bluff-body or propagating in ducts are revealed. Elementary components of the flame propagation process are shown to be: rotary motion, self-advancement, and expansion. Their consequences are analyzed under a most strict set of idealizations that permit the flow field to be treated as potential in character, while the flame is modelled as a Stefan-like interface capable of exerting a feed-back effect upon the flow field. The results provide an insight into the fundamental fluid-mechanical reasons for the experimentally observed distortions of the flame front, rationalizing in particular its ability to sustain relatively high flow velocities at amazingly low normal burning speeds.

  16. Damping of multispan heat exchanger tubes. Pt. 1: in gases

    International Nuclear Information System (INIS)

    Pettigrew, M.J.; Goyder, H.G.D.; Qiao, Z.L.; Axisa, F.

    1986-07-01

    Flow-induced vibration analyses of heat exchanger tubes require the knowledge of damping. This paper treats the question of damping on multispan heat exchanger tubes in air and gases. The different energy dissipation mechanisms that contribute to tube damping are discussed. The available experimental data are reviewed and analysed. We find that the main damping mechanism in gases is friction between tube and tube-supports. Damping is strongly related to tube-support thickness. Damping values are recommended for design purposes. This study is interesting in the nuclear industry for it often uses heat exchangers

  17. Emissions of greenhouse gases in the United States 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    This is the sixth annual report on aggregate US national emissions of greenhouse gases. It covers emissions over the period 1990--1996, with preliminary estimates of emissions for 1997. Chapter one summarizes some background information about global climate change and the greenhouse effect. Important recent developments in global climate change activities are discussed, especially the third Conference of the Parties to the Framework Convention on Climate Change, which was held in December of 1997 in Kyoto, Japan. Chapters two through five cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons and related gases, respectively. Chapter six describes potential sequestration and emissions of greenhouse gases as a result of land use changes. Six appendices are included in the report. 96 refs., 38 tabs.

  18. Spectrum of spin waves in cold polarized gases

    Energy Technology Data Exchange (ETDEWEB)

    Andreeva, T. L., E-mail: phdocandreeva@yandex.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2017-02-15

    The spin dynamics of cold polarized gases are investigated using the Boltzmann equation. The dispersion relation for spin waves (transverse component of the magnetic moment) and the spin diffusion coefficient of the longitudinal component of the magnetic moment are calculated without using fitting parameters. The spin wave frequency and the diffusion coefficient for rubidium atoms are estimated numerically.

  19. Quantum information entropies of ultracold atomic gases in a ...

    Indian Academy of Sciences (India)

    bosonic systems and a ≃ 1.982 and b = 1 for ideal fermionic systems. These results obey the entropic uncertainty relation given by Beckner, Bialynicki-Birula and Myceilski. Keywords. Ultracold atomic gases; information entropy; foundations of quantum mechanics. PACS Nos 67.85.−d; 89.70.Cf; 03.65.Ta. 1. Introduction.

  20. Tropospheric chemistry over the lower Great Plains of the United States. 2. Trace gas profiles and distributions

    Science.gov (United States)

    Luke, Winston T.; Dickerson, Russell R.; Ryan, William F.; Pickering, Kenneth E.; Nunnermacker, Linda J.

    1992-12-01

    Convective clouds and thunderstorms redistribute air pollutants vertically, and by altering the chemistry and radiative balance of the upper troposphere, these local actions can have global consequences. To study these effects, measurements of trace gases ozone, O3, carbon monoxide, CO, and odd nitrogen were made aboard the NCAR Sabreliner on 18 flights over the southern Great Plains during June 1985. To demonstrate chemical changes induced by vertical motions in the atmosphere and to facilitate comparison with computer model calculations, these data were categorized according to synoptic flow patterns. Part 1 of this two-part paper details the alternating pulses of polar and maritime air masses that dominate the vertical mixing in this region. In this paper, trace gas measurements are presented as altitude profiles (0-12 km) with statistical distributions of mixing ratios for each species in each flow pattern. The polar flow regime is characterized by northwesterly winds, subsiding air, and convective stability. Concentrations of CO and total odd nitrogen (NOy) are relatively high in the shallow planetary boundary layer (PBL) but decrease rapidly with altitude. Ozone, on the other hand, is uniformly distributed, suggesting limited photochemical production; in fact, nitric oxide, NO, mixing ratios fell below 10 ppt (parts per 1012 by volume) in the midtroposphere. The maritime regime is characterized by southerly surface winds, convective instability, and a deep PBL; uniformly high concentrations of trace gases were found up to 4 km on one flight. Severe storms occur in maritime flow, especially when capped by a dry layer, and they transport large amounts of CO, O3, and NOy into the upper troposphere. Median NO levels at high altitude exceeded 300 ppt. Lightning produces spikes of NO (but not CO) with mixing ratios sometimes exceeding 1000 ppt. This flow pattern tends to leave the midtroposphere relatively clean with concentrations of trace gases similar to those

  1. Throat gases against the CO2

    International Nuclear Information System (INIS)

    Michaut, C.

    2006-01-01

    The steel production needs carbon consumption and generates carbon dioxide, the main greenhouse gases. It represents about 6 % of the greenhouse gases emissions in the world. That is why the steel industry began last year a research program, Ideogaz, to reduce its CO 2 releases. The first results on the throat gases recovery seems very promising: it uses 25 % less of carbon. The author presents the program and the main technical aspects of the method. (A.L.B.)

  2. Optical Lattice Gases of Interacting Fermions

    Science.gov (United States)

    2015-12-02

    interacting Fermi gases has topological properties similar to the conventional chiral p- wave state. These include a non-zero Chern number and the...interacting cold gases with broad impacts on the interfaces with condensed matter and particle physics . Applications and experiments of some of the physics ...AFRL-AFOSR-VA-TR-2016-0016 Optical Lattice Gases of Interacting Fermions Wensheng Vincent Liu UNIVERSITY OF PITTSBURGH Final Report 12/02/2015

  3. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  4. Gender and Boyle's law of gases

    CERN Document Server

    Potter, Elizabeth

    2001-01-01

    Gender and Boyle''s Law of GasesElizabeth PotterRe-examines the assumptions and experimental evidence behind Boyle''s Law.Boyle''s Law, which describes the relation between the pressure and volume of a gas, was worked out by Robert Boyle in the mid-1600s. His experiments are still considered examples of good scientific work and continue to be studied along with their historical and intellectual contexts by philosophers, historians, and sociologists. Now there is controversy over whether Boyle''s work was based only on experimental evidence or whether it was influenced by the politics and religious controversies of the time, including especially class and gender politics.Elizabeth Potter argues that even good science is sometimes influenced by such issues, and she shows that the work leading to the Gas Law, while certainly based on physical evidenc...

  5. Critical discharge of fluids and gases

    International Nuclear Information System (INIS)

    Seewald, Michael

    2012-01-01

    The thermal hydraulic relations during discharge of fluids and gases are complex and a closed solution does not seem to be available. For the modeling of leakage accidents in nuclear power plants basic considerations are suitable for statements on the maximum mass flow, and thus the leak rate. The maximum mass flow is reached when the critical velocity is reached in the smallest cross section. This allows the appropriate design of safety systems for one-phase and two-phase flows. For German NPP simulators the hydrodynamics simulation program RELAP5-3D is used. The simulator center operates a 1:10 scale gas model of a two-loop PWR type reactor. The observable phenomena have occurred in nuclear power plants. The characteristics for a visualization of two-phase flows are not available in the simulation software and have to be added by correlations with experimental results. The realization of expectations on digital visualization techniques is discussed.

  6. Genetic implications for forest trees of increasing levels of greenhouse gases and UV-B radiation

    Science.gov (United States)

    David F. Karnosky; Kevin E. Percy; Blanka Mankovska

    2000-01-01

    Globally, the environment is changing and deteriorating as greenhouse gases such as carbon dioxide (CO2) and tropospheric ozone (03) continue to increase at a rate of about 1% per year (Keeling et al. 1995, Chameides et al. 1995). The increase in these gases is directly related to anthropogenic activities (Chameides et al...

  7. Noble gases in nuclear medicine

    International Nuclear Information System (INIS)

    Calderon, M.; Burdine, J.A.

    1973-01-01

    Radioactive noble gases have made a significant contribution to diagnostic nuclear medicine. In the area of regional assessment of pulmonary function, 133 Xe has had its greatest clinical impact. Following a breath of 133 Xe gas, pulmonary ventilation can be measured using a scintillation camera or other appropriate radiation detector. If 133 Xe dissolved in saline is injected intravenously, both pulmonary capillary perfusion and ventilation can be measured since 90 percent of the highly insoluble xenon escapes into the alveoli during the first passage through the lungs. Radionuclide pulmonary function tests provide the first qualitative means of assessing lung ventilation and blood flow on a regional basis, and have recently been extended to include quantification of various parameters of lung function by means of a small computer interfaced to the scintillation camera. 133 Xe is also used in the measurement of organ blood flow following injection into a vessel leading into an organ such as the brain, heart kidneys, or muscles

  8. Trace element analysis: a diagnostic tool

    International Nuclear Information System (INIS)

    Qureshi, I.H.; Cheema, M.N.

    1976-09-01

    The human mody continuously assimilates a variety of elements from the environment, and the concentration of these elements in the blood is regulated by means of various homeostatic mechanisms. Some of the elements, though present in very small amounts, have highly specialized functions in initiating many biochemical reactions. These elements, known as essential trace elements, are closely related to human diseases since their deficiency or excess induces physiological changes. Many diseases such as hypertension, atherosclerosis, diabetes, etc., are related to an imbalance in trace element. The measurement of trace elements in body fluids and tissues can, therefore, be effectively employed for diagnostic tests

  9. Energy efficiency and greenhouse gases

    International Nuclear Information System (INIS)

    Hamburg, A.; Martins, A.; Pesur, A.; Roos, I.

    1996-01-01

    Estonia's energy balance for 1990 - 1994 is characterized by the dramatic changes in the economy after regaining independence in 1991. In 1990 - 1993, primary energy supply decreased about 1.9 times. The reasons were a sharp decrease in exports of electric energy and industrial products, a steep increase in fuel prices and the transition from the planned to a market-oriented economy. Over the same period, the total amount of emitted greenhouse gases decreased about 45%. In 1993, the decrease in energy production and consumption stopped, and in 1994, a moderate increase occurred (about 6%), which is a proof stabilizing economy. Oil shale power engineering will remain the prevailing energy resource for the next 20 - 25 years. After stabilization, the use of oil shale will rise in Estonia's economy. Oil shale combustion in power plants will be the greatest source of greenhouse gases emissions in near future. The main problem is to decrease the share of CO 2 emissions from the decomposition of carbonate part of oil shale. This can be done by separating limestone particles from oil shale before its burning by use of circulating fluidized bed combustion technology. Higher efficiency of oil shale power plants facilitates the reduction of CO 2 emissions per generated MWh electricity considerably. The prognoses for the future development of power engineering depend essentially on the environmental requirements. Under the highly restricted development scenario, which includes strict limitations to emissions (CO 2 , SO 2 , thermal waste) and a severe penalty system, the competitiveness of nuclear power will increase. The conceptual steps taken by the Estonian energy management should be in compliance with those of neighboring countries, including the development programs of the other Baltic states

  10. Trace element partitioning in rock forming minerals of co-genetic, subduction-related alkaline and tholeiitic mafic rocks in the Ural Mountains, Russia

    Science.gov (United States)

    Krause, J.; Brügmann, G. E.; Pushkarev, E. V.

    2009-04-01

    The partitioning of trace elements between rock forming minerals in igneous rocks is largely controlled by physical and chemical parameters e.g. temperature, pressure and chemical composition of the minerals and the coexisting melt. In the present study partition coefficients for REE between hornblende, orthopyroxene, feldspars, apatite and clinopyroxene in a suite of co-genetic alkaline and tholeiitic mafic rocks from the Ural Mountains (Russia) were calculated. The results give insights to the influence of the chemical composition of the parental melt on the partitioning behaviour of the REE. Nepheline-bearing, alkaline melanogabbros (tilaites) are assumed to represent the most fractionated products of the melt that formed the ultramafic cumulates in zoned mafic-ultramafic complexes in the Ural Mountains. Co-genetic with the latter is a suite of olivine gabbros, gabbronorites and hornblende gabbros formed from a tholeiitic parental melt. Negative anomalies for the HFSE along with low Nb and Ta contents and a positive Sr anomaly indicate a subduction related origin of all parental melts. The nepheline gabbros consist predominantly of coarse-grained clinopyroxene phenocrysts in a matrix of fine grained clinopyroxene, olivine, plagioclase, K-feldspar and nepheline with accessory apatite. The tholeiitic gabbros have equigranular to porphyric textures with phenocrysts of olivine, pyroxene and hornblende in a plagioclase rich matrix with olivine hornblende, pyroxene and accessory apatite. Element concentrations of adjacent matrix grains and rims of phenochrysts were measured with LA-ICPMS. The distribution of REE between hornblende and clinopyroxene in the tholeiitic rocks is similar for most of the elements (DHbl•Cpx(La-Tm) = 2.7-2.8, decreasing to 2.6 and 2.4 for Yb and Lu, respectively). These values are about two times higher than published data (e.g. Ionov et al. 1997). Partition coefficients for orthopyroxene/clinopyroxene systematically decrease from the HREE

  11. Measurements of trace contaminants in closed-type plant cultivation chambers

    Science.gov (United States)

    Tani, A.; Kiyota, M.; Aiga, I.; Nitta, K.; Tako, Y.; Ashida, A.; Otsubo, K.; Saito, T.

    Trace contaminants generated in closed facilities can cause abnormal plant growth. We present measurement data of trace contaminants released from soils, plants, and construction materials. We mainly used two closed chambers, a Closed-type Plant and Mushroom Cultivation Chamber (PMCC) and Closed-type Plant Cultivation Equipment (CPCE). Although trace gas budgets from soils obtained in this experiment are only one example, the results indicate that the budgets of trace gases, as well as CO_2 and O_2, change greatly with the degree of soil maturation and are dependent on the kind of substances in the soil. Both in the PMCC and in the CPCE, trace gases such as dioctyl phthalate (DOP), dibutyl phthalate (DBP), toluene and xylene were detected. These gases seemed to be released from various materials used in the construction of these chambers. The degree of increase in these trace gas levels was dependent on the relationship between chamber capacity and plant quantity. Results of trace gas measurement in the PMCC, in which lettuce and shiitake mushroom were cultivated, showed that ethylene was released both from lettuce and from the mushroom culture bed. The release rates were about 90 ng bed^-1 h^-1 for the shiitake mushroom culture bed (volume is 1700 cm^3) and 4.1 ~ 17.3 ng dm^-2h^-1 (leaf area basis) for lettuce. Higher ethylene release rates per plant and per unit leaf area were observed in mature plants than in young plants.

  12. Improved mapping of tropospheric air quality gases based on the Copernicus Sentinel 5 Precursor/TROPOMI mission

    Science.gov (United States)

    Van Roozendael, Michel; De Smedt, Isabelle; Theys, Nicolas; Danckaert, Thomas; Yu, Huan; Lerot, Christophe; van Gent, Jeroen; Vlietinck, Jonas

    2017-04-01

    Scheduled for launch in summer 2017, the Sentinel 5 Precursor (S5P) mission having onboard the TROPOMI payload will fly on a sun-synchronous polar orbit and provide daily global early-afternoon observations of a number of key atmospheric trace gases at the unprecedented spatial resolution of 7x3.5 km2. By the early 2020's, S5P will be complemented by geostationary observations from the Sentinel 4 UVN instrument to be delivered at hourly resolution over Europe, and by mid-morning global observations from the low-earth orbiting Sentinel 5 mission. Altogether these missions will form a constellation serving the needs of the Copernicus Atmospheric Monitoring Services (CAMS). Owing to their unprecedented spatial resolution and spectral performance, TROPOMI/S5P and the subsequent Sentinel 4 and 5 missions will significantly push forward monitoring capabilities addressing anthropogenic and natural emissions of air quality-related trace gases. They will also extend the long-term datasets from past and existing UV-Vis sensors (GOME, SCIAMACHY, OMI, GOME-2, OMPS). In this presentation, we explore the potential of S5P to improve on several aspects of the monitoring of tropospheric pollutants, with a focus on the short-lived species NO2, SO2 and HCHO. Based on algorithms designed at BIRA as part of TROPOMI/S5P and S4/S5 level-2 development projects, and their application to the current OMI and GOME-2 sensors, we illustrate and discuss the expected ability of the new sensors to detect smaller scale point sources with better accuracy and selectivity. The retrieval challenges associated with higher resolution measurements are also addressed.

  13. Poisoning of bees with fluorine-containing industrial waste gases in Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Maurizio, A; Staub, M

    1956-01-01

    Mass poisoning of bees in the vicinity of Swiss Al factories was traced to high quantities of F in the waste gases. Plants and pollen in the vicinity contained 10-214 and 0.9-2.8 mg. % F resp., and collected rain water contained 0.1-10.4 mg. F/sg. dm. The dead bees each contained an av. of 15 ..gamma.. F.

  14. EOSN: A TOUGH2 module for noble gases

    International Nuclear Information System (INIS)

    Shan, Chao; Pruess, Karsten

    2003-01-01

    We developed a new fluid property module for TOUGH2, called EOSN, to simulate transport of noble gases in the subsurface. Currently, users may select any of five different noble gases as well as CO2, two at a time. For the three gas components (air and two user-specified noble gases) in EOSN, the Henry's coefficients and the diffusivities in the gas phase are no longer assumed constants, but are temperature dependent. We used the Crovetto et al. (1982) model to estimate Henry's coefficients, and the Reid et al. (1987) correlations to calculate gas phase diffusivities. The new module requires users to provide names of the selected noble gases, which properties are provided internally. There are options for users to specify any (non-zero) molecular weights and half-lives for the gas components. We provide two examples to show applications of TOUGH2IEOSN. While temperature effects are relatively insignificant for one example problem where advection is dominant, they cause almost an order of magnitude difference for the other case where diffusion becomes a dominant process and temperature variations are relatively large. It appears that thermodynamic effects on gas diffusivities and Henry's coefficients can be important for low-permeability porous media and zones with large temperature variations

  15. EOSN: A TOUGH2 module for noble gases

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Chao; Pruess, Karsten

    2003-03-07

    We developed a new fluid property module for TOUGH2, called EOSN, to simulate transport of noble gases in the subsurface. Currently, users may select any of five different noble gases as well as CO2, two at a time. For the three gas components (air and two user-specified noble gases) in EOSN, the Henry's coefficients and the diffusivities in the gas phase are no longer assumed constants, but are temperature dependent. We used the Crovetto et al. (1982) model to estimate Henry's coefficients, and the Reid et al. (1987) correlations to calculate gas phase diffusivities. The new module requires users to provide names of the selected noble gases, which properties are provided internally. There are options for users to specify any (non-zero) molecular weights and half-lives for the gas components. We provide two examples to show applications of TOUGH2IEOSN. While temperature effects are relatively insignificant for one example problem where advection is dominant, they cause almost an order of magnitude difference for the other case where diffusion becomes a dominant process and temperature variations are relatively large. It appears that thermodynamic effects on gas diffusivities and Henry's coefficients can be important for low-permeability porous media and zones with large temperature variations.

  16. 40 CFR 89.312 - Analytical gases.

    Science.gov (United States)

    2010-07-01

    ... determined to calibration gas tolerances by chromatographic analysis of total hydrocarbons plus impurities or.... (2) Mixtures of gases having the following chemical compositions shall be available: (i) C3H8 and... check gases shall contain propane with 350 ppmC ±75 ppmC hydrocarbon. The three oxygen interference...

  17. Greenhouse Gases Concentrations in the Atmosphere Along ...

    African Journals Online (AJOL)

    This study investigated effect of vehicular emission on greenhouse gases concentrations along selected roads of different traffic densities in Abeokuta, Ogun State, Nigeria. Nine roads comprised highway, commercial and residential were selected. Greenhouse Gases (GHGs) were determined from both sides of the roads by ...

  18. Specific heats of degenerate ideal gases

    OpenAIRE

    Caruso, Francisco; Oguri, Vitor; Silveira, Felipe

    2017-01-01

    From arguments based on Heisenberg's uncertainty principle and Pauli's exclusion principle, the molar specific heats of degenerate ideal gases at low temperatures are estimated, giving rise to values consistent with the Nerst-Planck Principle (third law of Thermodynamics). The Bose-Einstein condensation phenomenon based on the behavior of specific heat of massive and non-relativistic boson gases is also presented.

  19. Method for storing radioactive rare gases

    International Nuclear Information System (INIS)

    Watabe, Atsushi; Nagao, Hiroyuki; Takiguchi, Yukio; Kanazawa, Toshio; Soya, Masataka.

    1975-01-01

    Object: To safely and securely store radioactive rare gases for a long period of time. Structure: The waste gases produced in nuclear power plant are cooled by a cooler and then introduced into a low temperature adsorbing device so that the gases are adsorbed by adsorbents, and then discharged into atmosphere through the purifying gas discharge line. When the radioactive rare gases reach a level of saturation in the amount of adsorption, they are heated and extracted by a suction pump and heated by a heater. The gases are then introduced into an oxygen-impurity removing device and the purified rare gases containing no oxygen and impurities are cooled by a cooler and fed into a gas holder. When the amount of radioactive rare gases stored within the gas holder reaches a given level, they are compressed and sealed by a compressure into a storing cylinder and residual gases in the piping are sucked and recovered into the gas holder, after which the cylinder is removed and stored in a fixed room. (Kamimura, M.)

  20. Lessons from geothermal gases at Yellowstone

    Science.gov (United States)

    Lowenstern, J. B.; Bergfeld, D.; Evans, W.; Hurwitz, S.

    2015-12-01

    The magma-hydrothermal system of the Yellowstone Plateau Volcanic Field encompasses over ten thousand individual springs, seeps, and fumaroles spread out over >9000 square kilometers, and produces a range of acid, neutral and alkaline waters. A prominent model (Fournier, 1989 and related papers) concludes that many neutral and alkaline fluids found in hot springs and geysers are derived from a uniform, high-enthalpy parent fluid through processes such as deep boiling and mixing with dilute meteoric groundwater. Acid waters are generally condensates of gas-bearing steam that boils off of subsurface geothermal waters. Our recent studies of gases at Yellowstone (Lowenstern et al., 2015 and references therein) are compatible with such a model, but also reveal that gases are largely decoupled from thermal waters due to open-system addition of abundant deep gas to (comparatively) shallow circulating thermal waters. Fumarole emissions at Yellowstone range from gas-rich (up to 15 mol%) composed of deeply derived CO2, He and CH4, to steam-rich emissions (16 RA) and low CH4 and He concentrations and 2) mantle-derived CO2 with much higher CH4 and/or He concentrations and abundant radiogenic He picked up from crustal degassing. Individual thermal areas have distinct CH4/He. It remains unclear whether some gas ratios mainly reflect subsurface geothermal temperatures. Instead, they may simply reflect signatures imparted by local rock types and mixing on timescales too fast for reequilibration. Overall, the gas chemistry reflects a broader view of mantle-crust dynamics than can be appreciated by studies of only dissolved solutes in the neutral and alkaline waters from Yellowstone geysers. Fournier (1989) Ann. Rev. Earth Planet. Sci. v. 17, p. 13-53. Lowenstern et al. (2015) JVGR, v. 302, 87-101.

  1. Computer ray tracing speeds.

    Science.gov (United States)

    Robb, P; Pawlowski, B

    1990-05-01

    The results of measuring the ray trace speed and compilation speed of thirty-nine computers in fifty-seven configurations, ranging from personal computers to super computers, are described. A correlation of ray trace speed has been made with the LINPACK benchmark which allows the ray trace speed to be estimated using LINPACK performance data. The results indicate that the latest generation of workstations, using CPUs based on RISC (Reduced Instruction Set Computer) technology, are as fast or faster than mainframe computers in compute-bound situations.

  2. Method of contacting solids and gases

    Energy Technology Data Exchange (ETDEWEB)

    1942-08-06

    A continuous method is described for contacting solids and gases. The process involves passing a confined stream of gases through an extended path including a treating zone and imposing a pressure on the stream of gases at least sufficient to overcome the resistence of said path to the flow of said gases. A solid in finely divided form is then introduced into said stream of gases, maintaining a vertical column of finely divided solid in fluidized state of a height which will produce a pressure at the column bottom at least equal to the gas pressure at the point of entry of the solids into the stream. The solids then pass from the bottom of the column into the stream.

  3. Weekly cycle of minor air gases in Moscow

    Science.gov (United States)

    Lokoshchenko, Mikhail A.; Elansky, Nikolay F.; Trifanova, Alexandra V.

    2017-04-01

    The weekly cycle of the surface concentrations of five trace atmospheric gases in Moscow has been analyzed based on continuous automatic once-a-minute measurements. The data of joint ecological station of the Institute of Atmospheric Physics and Moscow State University for nine years (2002-2010) were used. This station operated in conditions of comparatively clear park zone of the University on the South-Western periphery of the city at a distance of 8 km from the city centre. Fortunately, none of the great sources of the air pollution - neither point sources, nor linear ones - are present in the vicinity of the station so that the measurements there are quite representative. Results of spectral analysis demonstrate statistically significant maximum of spectral density close to 7 days. Any clear periodicity of around seven days may be a consequence of either natural synoptic period or weekly cycle. The fact that the influence of human activity on urban air composition changes with a weekly periodicity is confirmed by statistically significant difference between concentrations of trace gases on working days and on Sunday (when emissions from both the traffic and the industrial sources are minimal). On average, both primary pollutants (nitrogen oxide and carbon oxide) and the secondary ones (NO2) show the lowest concentrations of the week on Sunday whereas ozone, by contrast, peaks on this day. Besides, usual diurnal cycle of air pollutants is transformed on Sunday - e.g., secondary nocturnal maximum of ozone in the city is absent on Sunday like at rural area. On Saturday concentrations of trace gases are in between working days and Sunday; this 'Saturday effect' is a result of a gradual clearing of the urban air. An additional effect is that in the first half of Monday (before noon) surface concentrations of NO and NO2 are generally less, whereas the concentration of O3 is, on the contrary, a bit higher than at the same time on the rest of working days. The 'Monday

  4. Trace level detection of compounds related to the chemical weapons convention by 1H-detected 13C NMR spectroscopy executed with a sensitivity-enhanced, cryogenic probehead.

    Science.gov (United States)

    Cullinan, David B; Hondrogiannis, George; Henderson, Terry J

    2008-04-15

    Two-dimensional 1H-13C HSQC (heteronuclear single quantum correlation) and fast-HMQC (heteronuclear multiple quantum correlation) pulse sequences were implemented using a sensitivity-enhanced, cryogenic probehead for detecting compounds relevant to the Chemical Weapons Convention present in complex mixtures. The resulting methods demonstrated exceptional sensitivity for detecting the analytes at trace level concentrations. 1H-13C correlations of target analytes at chemical shift information could be derived quickly and simultaneously from the resulting spectra. The fast-HMQC pulse sequences generated magnitude mode spectra suitable for detailed analysis in approximately 4.5 h and can be used in experiments to efficiently screen a large number of samples. The HSQC pulse sequences, on the other hand, required roughly twice the data acquisition time to produce suitable spectra. These spectra, however, were phase-sensitive, contained considerably more resolution in both dimensions, and proved to be superior for detecting analyte 1H-13C correlations. Furthermore, a HSQC spectrum collected with a multiplicity-edited pulse sequence provided additional structural information valuable for identifying target analytes. The HSQC pulse sequences are ideal for collecting high-quality data sets with overnight acquisitions and logically follow the use of fast-HMQC pulse sequences to rapidly screen samples for potential target analytes. Use of the pulse sequences considerably improves the performance of NMR spectroscopy as a complimentary technique for the screening, identification, and validation of chemical warfare agents and other small-molecule analytes present in complex mixtures and environmental samples.

  5. Kinetic Theory of Granular Gases

    Energy Technology Data Exchange (ETDEWEB)

    Trizac, Emmanuel [Center of Theoretical Biological Physics, UC San Diego, La Jolla, CA 92093-0374 (United States); Laboratoire de Physique Theorique et Modeles Statistiques, Campus Universitaire, 91405 Orsay (France)

    2005-11-25

    Granular gases are composed of macroscopic bodies kept in motion by an external energy source such as a violent shaking. The behaviour of such systems is quantitatively different from that of ordinary molecular gases: due to the size of the constituents, external fields have a stronger effect on the dynamics and, more importantly, the kinetic energy of the gas is no longer a conserved quantity. The key role of the inelasticity of collisions has been correctly appreciated for about fifteen years, and the ensuing consequences in terms of phase behaviour or transport properties studied in an increasing and now vast body of literature. The purpose of this book is to help the newcomer to the field in acquiring the essential theoretical tools together with some numerical techniques. As emphasized by the authors-who were among the pioneers in the domain- the content could be covered in a one semester course for advanced undergraduates, or it could be incorporated in a more general course dealing with the statistical mechanics of dissipative systems. The book is self-contained, clear, and avoids mathematical complications. In order to elucidate the main physical ideas, heuristic points of views are sometimes preferred to a more rigorous route that would lead to a longer discussion. The 28 chapters are short; they offer exercises and worked examples, solved at the end of the book. Each part is supplemented with a relevant foreword and a useful summary including take-home messages. The editorial work is of good quality, with very few typographical errors. In spite of the title, kinetic theory stricto sensu is not the crux of the matter covered. The authors discuss the consequences of the molecular chaos assumption both at the individual particle level and in terms of collective behaviour. The first part of the book addresses the mechanics of grain collisions. It is emphasized that considering the coefficient of restitution {epsilon} -a central quantity governing the

  6. Kinetic Theory of Granular Gases

    International Nuclear Information System (INIS)

    Trizac, Emmanuel

    2005-01-01

    Granular gases are composed of macroscopic bodies kept in motion by an external energy source such as a violent shaking. The behaviour of such systems is quantitatively different from that of ordinary molecular gases: due to the size of the constituents, external fields have a stronger effect on the dynamics and, more importantly, the kinetic energy of the gas is no longer a conserved quantity. The key role of the inelasticity of collisions has been correctly appreciated for about fifteen years, and the ensuing consequences in terms of phase behaviour or transport properties studied in an increasing and now vast body of literature. The purpose of this book is to help the newcomer to the field in acquiring the essential theoretical tools together with some numerical techniques. As emphasized by the authors-who were among the pioneers in the domain- the content could be covered in a one semester course for advanced undergraduates, or it could be incorporated in a more general course dealing with the statistical mechanics of dissipative systems. The book is self-contained, clear, and avoids mathematical complications. In order to elucidate the main physical ideas, heuristic points of views are sometimes preferred to a more rigorous route that would lead to a longer discussion. The 28 chapters are short; they offer exercises and worked examples, solved at the end of the book. Each part is supplemented with a relevant foreword and a useful summary including take-home messages. The editorial work is of good quality, with very few typographical errors. In spite of the title, kinetic theory stricto sensu is not the crux of the matter covered. The authors discuss the consequences of the molecular chaos assumption both at the individual particle level and in terms of collective behaviour. The first part of the book addresses the mechanics of grain collisions. It is emphasized that considering the coefficient of restitution ε -a central quantity governing the inelasticity of

  7. The storage of greenhouse gases

    International Nuclear Information System (INIS)

    Herzog, H.; Kaarstad, O.; Eliasson, B

    2000-01-01

    Since 1850, that is to say the beginning of the industrial era,the concentration of carbon dioxide in the atmosphere has risen from 280 ppm to 370 ppm, this increase is mainly due to the combustion of fossil fuels. Today fossil fuels represent 85% of all the energy used in the world. Fearing progressive climatic changes, more and more governments become aware of the necessity of reducing the emission of greenhouse gases. A more efficient use of energy and the promoting of renewable energies and of the nuclear energy are the most evident solutions but they appear to be insufficient. A third solution is the storage of carbon dioxide in geological layers. This technique has been put into use since 1996 in Norway. An off-shore natural gas platform injects carbon dioxide in a geological reservoir situated 1000 meters below the ocean bed. The injection of CO 2 could be used in oil fields in order to facilitate the extraction of petroleum. Far more large and efficient reservoirs would be the oceans, they already hold up 40000 10 9 tons of dissolved CO 2 . Even if the double of the carbon dioxide accumulated in the atmosphere since 1850 were injected, the concentration of carbon in sea waters would rise by less than 2%. The safety of CO 2 storage and the impact on the environment of ocean injection sites are being studied. (A.C.)

  8. Greenhouse gases and emissions trading

    International Nuclear Information System (INIS)

    LeBlanc, A.; Dudek, D.J.

    1993-01-01

    Global cooperation is essential in cutting greenhouse-gas emissions, say Alice LeBlanc and Daniel J. Dudek of the Environmental Defense in New York City. The first step, they continue, is agreement among nations on an overall global limit for all greenhouse gases, followed by an allocation of the global limit among nations. The agreements must contain effective reporting and monitoring systems and enforcement provisions, they add. The Framework Convention on Climate Change, signed by most nations of the world in Brazil in 1992, provides the foundation for such an agreement, LeBlanc and Dudek note. open-quotes International emissions trading is a way to lower costs and expand reduction options for the benefit of all,close quotes they contend. Under such an arrangement, an international agency would assign allowances, stated in tons of carbon dioxide. Countries would be free to buy and sell allowances, but no country could exceed, in a given year, the total allowances it holds. By emitting less than its allowed amount, a country would accumulate more allowances, which it could sell. The authors claim such a system would offer benefits to the world economy by saving billions of dollars in pollution-reduction costs while still achieving emission limits established in an international agreement

  9. Resonance ionization and time-of-flight mass spectrometry for the analysis of trace substances in complex gas mixtures

    International Nuclear Information System (INIS)

    Nagel, Holger; Weickhardt, Christian; Boesl, Ulrich; Frey, Ruediger

    1995-01-01

    The analysis of mixtures of technical gases still comprises a lot of problems: the large number of components with very different and often rapidly varying concentrations makes great demands on analytical methods. By use of conventional analytical methods, signals of trace substances may interfere with signals of main components, whereas small signals representing low concentrations are covered by signals of main substances.The resonant-enhanced multiphoton ionization (REMPI) makes use of excited intermediate states of molecules. As these states are characteristic of each substance, one or more components of interest can be ionized with high efficiency without interference of other molecules by using a special laser-wavelength. The combination of the above mentioned ionization method with a reflectron time-of-flight mass spectrometer permits a very fast and sensitive detection of preselected trace substances.As ionization processes of higher order strongly depend on the laser intensity, there is no direct relation between ion signals and concentrations of exhaust components. Quantitative assessments are based on an especially developed calibration technique that makes use of internal standards. Applied under environmental aspects, this new analytical method helps to analyze a large number of components extracted from exhaust gases of combustion engines with high time resolution (<20 ms motor synchronously), high sensitivity (1 ppm) and high quantitative accuracy (more than 10%). A preliminary list of detectable compounds contains 30 substances

  10. Experimental investigation of solid oxide fuel cells using biomass gasification producer gases

    Energy Technology Data Exchange (ETDEWEB)

    Norheim, Arnstein

    2005-07-01

    The main objective of this thesis is theoretical and experimental investigations related to utilisation of biomass gasification producer gases as fuel for Solid Oxide Fuel Cells (SOFC). Initial fundamental steps towards a future system of combined heat and power production based on biomass gasification and SOFC are performed and include: 1) Theoretical modeling of the composition of biomass gasification producer gases. 2) Experimental investigation of SOFC performance using biomass gasification producer gas as fuel. 3) Experimental investigation of SOFC performance using biomass gasification producer gas containing high sulphur concentration. The modeling of the composition of gasifier producer gas was performed using the program FactSage. The main objective was to investigate the amount and speciation of trace species in the producer gases as several parameters were varied. Thus, the composition at thermodynamic equilibrium of sulphur, chlorine, potassium, sodium and compounds of these were established. This was done for varying content of the trace species in the biomass material at different temperatures and fuel utilisation i.e. varying oxygen content in the producer gas. The temperature interval investigated was in the range of normal SOFC operation. It was found that sulphur is expected to be found as H2S irrespective of temperature and amount of sulphur. Only at very high fuel utilisation some S02 is formed. Important potassium containing compounds in the gas are gaseous KOH and K. When chlorine is present, the amount of KOH and K will decrease due to the formation of KCI. The level of sodium investigated here was low, but some Na, NaOH and NaCl is expected to be formed. Below a certain temperature, condensation of alkali rich carbonates may occur. The temperature at which condensation begins is mainly depending on the amount of potassium present; the condensation temperature increases with increasing potassium content. In the first experimental work

  11. Traces of Drosophila Memory

    Science.gov (United States)

    Davis, Ronald L.

    2012-01-01

    Summary Studies using functional cellullar imaging of living flies have identified six memory traces that form in the olfactory nervous system after conditioning with odors. These traces occur in distinct nodes of the olfactory nervous system, form and disappear across different windows of time, and are detected in the imaged neurons as increased calcium influx or synaptic release in response to the conditioned odor. Three traces form at, or near acquisition and co-exist with short-term behavioral memory. One trace forms with a delay after learning and co-exists with intermediate-term behavioral memory. Two traces form many hours after acquisition and co-exist with long-term behavioral memory. The transient memory traces may support behavior across the time-windows of their existence. The experimental approaches for dissecting memory formation in the fly, ranging from the molecular to the systems, make it an ideal system for dissecting the logic by which the nervous system organizes and stores different temporal forms of memory. PMID:21482352

  12. The Effects of Supplementary Mulberry Leaf (Morus alba) Extracts on the Trace Element Status (Fe, Zn and Cu) in Relation to Diabetes Management and Antioxidant Indices in Diabetic Rats.

    Science.gov (United States)

    Król, Ewelina; Jeszka-Skowron, Magdalena; Krejpcio, Zbigniew; Flaczyk, Ewa; Wójciak, Rafał W

    2016-11-01

    Mulberry leaves (Morus alba) have been used in folk medicine to mitigate symptoms of diabetes. The mulberry plant contains phenolic compounds that are able to decrease blood glucose concentration. Since various phenolics have antioxidant and metal binding properties, they can be used to alleviate oxidative stress and chelate trace elements involved in redox reactions. The aim of this study was to evaluate the effects of dietary supplementation with mulberry leaf extracts (acetone-water (AE) and ethanol-water (EE)) on the trace element status (Fe, Zn and Cu) in relation to diabetes management and antioxidant indices in high-fat diet-fed/STZ diabetic rats. The experiment was performed on 38 male Wistar rats with diabetes (induced by high-fat diet (HF) and streptozotocin injection) or the control fed with AIN-93M or high-fat diet. As a result, five experimental groups were used: (1) a healthy control group fed with AIN-93M; (2) an HF control group; (3) a diabetic HF group; (4) a diabetic HF + AE group (6 g/kg diet); (5) a diabetic HF + EE group (6 g/kg diet). The rats were fed with appropriate diets for 4 weeks. The content of trace elements (Fe, Zn and Cu) in the serum and tissues was measured by means of atomic absorption spectrometry (AAS). Biochemical analyses (glucose, TBARS, FRAP) were performed on the blood serum. It was shown that the AE decreased hepatic and renal Fe stores, while the EE increased hepatic Cu levels in diabetic rats and confirmed their ability to regulate the Fe and Cu status in diabetes. The results confirmed a significant hypoglycaemic and antioxidant potential of both mulberry leaf extracts in diabetic rats.

  13. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between: Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or show little or no fine particle enrichment, examples include Mn, Be, Co and Cr; Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing enrichment with decreasing particle size, examples include As, Cd, Pb and Sb; Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review), and in some cases, Se). Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

  14. Semiclassical structure of trace formulas

    International Nuclear Information System (INIS)

    Littlejohn, R.G.

    1990-01-01

    Trace formulas provide the only general relations known connecting quantum mechanics with classical mechanics in the case that the classical motion is chaotic. In particular, they connect quantal objects such as the density of states with classical periodic orbits. In this paper, several trace formulas, including those of Gutzwiller, Balian and Bloch, Tabor, and Berry, are examined from a geometrical standpoint. New forms of the amplitude determinant in asymptotic theory are developed as tools for this examination. The meaning of caustics in these formulas is revealed in terms of intersections of Lagrangian manifolds in phase space. The periodic orbits themselves appear as caustics of an unstable kind, lying on the intersection of two Lagrangian manifolds in the appropriate phase space. New insight is obtained into the Weyl correspondence and the Wigner function, especially their caustic structures

  15. Comparison of natural gases accumulated in Oligocene strata with hydrous pyrolysis gases from Menilite Shales of the Polish Outer Carpathians

    Science.gov (United States)

    Kotarba, M.J.; Curtis, John B.; Lewan, M.D.

    2009-01-01

    This study examined the molecular and isotopic compositions of gases generated from different kerogen types (i.e., Types I/II, II, IIS and III) in Menilite Shales by sequential hydrous pyrolysis experiments. The experiments were designed to simulate gas generation from source rocks at pre-oil-cracking thermal maturities. Initially, rock samples were heated in the presence of liquid water at 330 ??C for 72 h to simulate early gas generation dominated by the overall reaction of kerogen decomposition to bitumen. Generated gas and oil were quantitatively collected at the completion of the experiments and the reactor with its rock and water was resealed and heated at 355 ??C for 72 h. This condition simulates late petroleum generation in which the dominant overall reaction is bitumen decomposition to oil. This final heating equates to a cumulative thermal maturity of 1.6% Rr, which represents pre-oil-cracking conditions. In addition to the generated gases from these two experiments being characterized individually, they are also summed to characterize a cumulative gas product. These results are compared with natural gases produced from sandstone reservoirs within or directly overlying the Menilite Shales. The experimentally generated gases show no molecular compositions that are distinct for the different kerogen types, but on a total organic carbon (TOC) basis, oil prone kerogens (i.e., Types I/II, II and IIS) generate more hydrocarbon gas than gas prone Type III kerogen. Although the proportionality of methane to ethane in the experimental gases is lower than that observed in the natural gases, the proportionality of ethane to propane and i-butane to n-butane are similar to those observed for the natural gases. ??13C values of the experimentally generated methane, ethane and propane show distinctions among the kerogen types. This distinction is related to the ??13C of the original kerogen, with 13C enriched kerogen generating more 13C enriched hydrocarbon gases than

  16. Essential Characteristics of Plasma Antennas Filled with He-Ar Penning Gases

    International Nuclear Information System (INIS)

    Sun Naifeng; Li Wenzhong; Wang Shiqing; Li Jian; Ci Jiaxiang

    2012-01-01

    Based on the essential theory of Penning gases, the discharge characteristics of He-Ar Penning gases in insulating tubes were analyzed qualitatively. The relation between the effective length of an antenna column filled with He-Ar Penning gases and the applied radio frequency (RF) power was investigated both theoretically and experimentally. The distribution of the plasma density along the antenna column in different conditions was studied. The receiving characteristics of local frequency modulated (FM) electromagnetic waves by the plasma antenna filled with He-Ar Penning gases were compared with those by an aluminum antenna with the same dimensions. Results show that it is feasible to take plasma antennas filled with He-Ar Penning gases as receiving antennas.

  17. Thermodynamics of ultracold Fermi gases

    International Nuclear Information System (INIS)

    Nascimbene, Sylvain

    2010-01-01

    Complex Hamiltonians from condensed matter, such as the Fermi-Hubbard model, can be experimentally studied using ultracold gases. This thesis describes a new method for determining the equation of state of an ultracold gas, making the comparison with many-body theories straightforward. It is based on the measurement of the local pressure inside a trapped gas from the analysis of its in situ image. We first apply this method to the study of a Fermi gas with resonant interactions, a weakly-interacting 7 Li gas acting as a thermometer. Surprisingly, none of the existing many-body theories of the unitary gas accounts for the equation of state deduced from our study over its full range. The virial expansion extracted from the high-temperature data agrees with the resolution of the three-body problem. At low temperature, we observe, contrary to some previous studies, that the normal phase behaves as a Fermi liquid. Finally we obtain the critical temperature for superfluidity from a clear signature on the equation of state. We also measure the pressure of the ground state as a function of spin imbalance and interaction strength - measure directly relevant to describe the crust of neutron stars. Our data validate Monte-Carlo simulations and quantify the Lee-Huang-Yang corrections to mean-field interactions in low-density fermionic or bosonic superfluids. We show that, in most cases, the partially polarized normal phase can be described as a Fermi liquid of polarons. The polaron effective mass extracted from the equation of state is in agreement with a study of collective modes. (author)

  18. From trace chemistry to single atom chemistry

    International Nuclear Information System (INIS)

    Adloff, J.P.

    1993-01-01

    Hot atom chemistry in the vast majority of experimental works deals with the trace amount of radioactive matters. Accordingly, the concept of trace chemistry is at the heart of hot atom chemistry. Some aspects of the chemistry at trace scale and at subtrace scale are presented together with the related problems of speciation and the complication which may arise due to the formation of radio colloids. The examples of 127 I(n,γ) 128 I and 132 Te (β - ) 132 I are shown, and the method based on radioactivity was used. The procedure of separating the elements in pitchblende is shown as the example of the chemistry of traces. 13 27 Al+ 2 4 He→ 0 1 n+ 15 30 P and 15 30 P→ 14 30 Si+e + +V are shown, and how to recognize the presence of radioactive colloids is explained. The formation of radiocolloids is by the sorption of a trace radioelement on pre-existing colloidal impurity or the self-condensation of monomeric species. The temporal parameters of the nature of reactions at trace concentration are listed. The examples of Class A and Class B reactions are shown. The kinetics of reactions at trace level, radon concentration, anthropogenic Pu and natural Pu in environment, the behavior of Pu atoms and so on are described. (K.I.)

  19. Recent Experimental Advances to Determine (noble) Gases in Waters

    Science.gov (United States)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial control of 220Rn occurrence in the environment

  20. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    KAUST Repository

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-01-01

    . These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015

  1. Trace explosives sensor testbed (TESTbed)

    Science.gov (United States)

    Collins, Greg E.; Malito, Michael P.; Tamanaha, Cy R.; Hammond, Mark H.; Giordano, Braden C.; Lubrano, Adam L.; Field, Christopher R.; Rogers, Duane A.; Jeffries, Russell A.; Colton, Richard J.; Rose-Pehrsson, Susan L.

    2017-03-01

    A novel vapor delivery testbed, referred to as the Trace Explosives Sensor Testbed, or TESTbed, is demonstrated that is amenable to both high- and low-volatility explosives vapors including nitromethane, nitroglycerine, ethylene glycol dinitrate, triacetone triperoxide, 2,4,6-trinitrotoluene, pentaerythritol tetranitrate, and hexahydro-1,3,5-trinitro-1,3,5-triazine. The TESTbed incorporates a six-port dual-line manifold system allowing for rapid actuation between a dedicated clean air source and a trace explosives vapor source. Explosives and explosives-related vapors can be sourced through a number of means including gas cylinders, permeation tube ovens, dynamic headspace chambers, and a Pneumatically Modulated Liquid Delivery System coupled to a perfluoroalkoxy total-consumption microflow nebulizer. Key features of the TESTbed include continuous and pulseless control of trace vapor concentrations with wide dynamic range of concentration generation, six sampling ports with reproducible vapor profile outputs, limited low-volatility explosives adsorption to the manifold surface, temperature and humidity control of the vapor stream, and a graphical user interface for system operation and testing protocol implementation.

  2. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    Science.gov (United States)

    Ayala, Raul E.

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  3. Spoken word recognition without a TRACE

    Science.gov (United States)

    Hannagan, Thomas; Magnuson, James S.; Grainger, Jonathan

    2013-01-01

    How do we map the rapid input of spoken language onto phonological and lexical representations over time? Attempts at psychologically-tractable computational models of spoken word recognition tend either to ignore time or to transform the temporal input into a spatial representation. TRACE, a connectionist model with broad and deep coverage of speech perception and spoken word recognition phenomena, takes the latter approach, using exclusively time-specific units at every level of representation. TRACE reduplicates featural, phonemic, and lexical inputs at every time step in a large memory trace, with rich interconnections (excitatory forward and backward connections between levels and inhibitory links within levels). As the length of the memory trace is increased, or as the phoneme and lexical inventory of the model is increased to a realistic size, this reduplication of time- (temporal position) specific units leads to a dramatic proliferation of units and connections, begging the question of whether a more efficient approach is possible. Our starting point is the observation that models of visual object recognition—including visual word recognition—have grappled with the problem of spatial invariance, and arrived at solutions other than a fully-reduplicative strategy like that of TRACE. This inspires a new model of spoken word recognition that combines time-specific phoneme representations similar to those in TRACE with higher-level representations based on string kernels: temporally independent (time invariant) diphone and lexical units. This reduces the number of necessary units and connections by several orders of magnitude relative to TRACE. Critically, we compare the new model to TRACE on a set of key phenomena, demonstrating that the new model inherits much of the behavior of TRACE and that the drastic computational savings do not come at the cost of explanatory power. PMID:24058349

  4. Anaesthetic gases: environmental impact and alternatives

    African Journals Online (AJOL)

    Little consideration has been given to the environmental impact of anaesthetic gas .... our practice to select gases with a lower environmental impact is also ... is used as raw material for new anaesthetics. ... none in the pipeline.1. Conclusion.

  5. Voluntary reporting of greenhouse gases, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The Voluntary Reporting Program for greenhouse gases is part of an attempt by the U.S. Government to develop innovative, low-cost, and nonregulatory approaches to limit emissions of greenhouse gases. It is one element in an array of such programs introduced in recent years as part of the effort being made by the United States to comply with its national commitment to stabilize emissions of greenhouse gases under the Framework Convention on Climate Change. The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report to the Energy Information Administration (EIA) on actions taken that have reduced or avoided emissions of greenhouse gases.

  6. Greenhouse gases - observed tendencies contra scenarios

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2006-01-01

    The article presents a study of the increase in greenhouse gases and concludes that it will be necessary to substantially reduce the CO2 concentrations in the atmosphere in order to avoid serious climatic changes

  7. Climate Change, Greenhouse Gases and Aerosols

    Indian Academy of Sciences (India)

    user

    their radiative properties are similar to the glass used in a green- house. Greenhouse gases in the Earth's atmosphere absorb 90% of the radiation emitted .... and wind speed and direction in each box is calculated using the physical laws gov-.

  8. Roadside management strategies to reduce greenhouse gases.

    Science.gov (United States)

    2010-06-01

    Californias Global Warming Solutions Act of 2006 (AB 32), Sustainable Communities and Climate Protection Act : (SB 375), and Executive Order S-14-08 direct Caltrans to develop actions to reduce greenhouse gases (GHGs). Air : pollution reduction is...

  9. [Emission and control of gases and odorous substances from animal housing and manure depots].

    Science.gov (United States)

    Hartung, J

    1992-02-01

    Agricultural animal production in increasingly regarded as a source of gases which are both aggravating and ecologically harmful. An overview of the origin, number and quantity of trace gases emitted from animal housing and from manure stores is presented and possible means of preventing or reducing them are discussed. Of the 136 trace gases in the air of animal houses, odorous substances, ammonia and methane are most relevant to the environment. The role played by the remaining gases is largely unknown. Quantitative information is available for 23 gases. The gases are emitted principally from freshly deposited and stored faeces, from animal feed and from the animals themselves. Future work should determine sources and quantities of the gases emitted from animal housing more precisely and should aim to investigate the potential of these gases to cause damage in man, animals and environment. Odorous substances have an effect on the area immediately surrounding the animal housing. They can lead to considerable aggravation in humans. For years, VDI1 guidelines (3471/72), which prescribe distances between residential buildings and animal housing, have been valuable in preventing odour problems of this kind. Coverings are suitable for outside stores. The intensity of the odour from animal housing waste air increases from cattle through to hens and pigs; it is also further affected by the type of housing, the age of the animals and the purpose for which they are being kept. Methods of cleaning waste air (scrubbers/biofilters) are available for problematic cases. The need for guidelines to limit emissions from individual outside manure stores (lagoons) is recognised. Total ammonia emissions from animal production in the Federal Republic of Germany (up to 1989) are estimated at approximately 300,000 to 600,000 t/year. There is a shortage of satisfactory and precise research on the extent of emissions, in particular on those from naturally ventilated housing. It is

  10. Gases for an SSC muon detector

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Datskos, P.G.; Carter, J.G.; Tennessee Univ., Knoxville, TN

    1990-01-01

    Recent measurements of electron drift velocities as a function of the density-reduced electric field E/N are reported for a number of unitary gases and the mixtures CO 2 /CH 4 and NH 3 /CF 4 /Ar. Calculated values of the mean electron energy as a function of E/N are also reported for unitary gases and mixtures of CO 2 /CH 4 . 7 refs., 5 figs

  11. Flux Jacobian Matrices For Equilibrium Real Gases

    Science.gov (United States)

    Vinokur, Marcel

    1990-01-01

    Improved formulation includes generalized Roe average and extension to three dimensions. Flux Jacobian matrices derived for use in numerical solutions of conservation-law differential equations of inviscid flows of ideal gases extended to real gases. Real-gas formulation of these matrices retains simplifying assumptions of thermodynamic and chemical equilibrium, but adds effects of vibrational excitation, dissociation, and ionization of gas molecules via general equation of state.

  12. Pseudogap phenomena in ultracold atomic Fermi gases

    OpenAIRE

    Chen, Qijin; Wang, Jibiao

    2014-01-01

    The pairing and superfluid phenomena in a two-component ultracold atomic Fermi gas is an analogue of Cooper pairing and superconductivity in an electron system, in particular, the high $T_c$ superconductors. Owing to the various tunable parameters that have been made accessible experimentally in recent years, atomic Fermi gases can be explored as a prototype or quantum simulator of superconductors. It is hoped that, utilizing such an analogy, the study of atomic Fermi gases may shed light to ...

  13. Quantum Fluctuations of Vortex Lattices in Ultracold Gases

    OpenAIRE

    Kwasigroch, M. P.; Cooper, N. R.

    2012-01-01

    We discuss the effects of quantum fluctuations on the properties of vortex lattices in rapidly rotating ultracold atomic gases. We develop a variational method that goes beyond the Bogoliubov theory by including the effects of interactions between the quasiparticle excitations. These interactions are found to have significant quantitative effects on physical properties even at relatively large filling factors. We use our theory to predict the expected experimental signatures of quantum fluctu...

  14. Gases and carbon in metals. Pt. 14

    International Nuclear Information System (INIS)

    Jehn, H.; Speck, H.; Hehn, W.; Fromm, E.; Hoerz, G.

    1981-01-01

    This issue is part of a series of data on 'Gases and Carbon in Metals' which supplements the data compilation in the book 'Gase und Kohlenstoff in Metallen' (Gases and Carbon in Metals), edited by E. Fromm and E. Gebhardt, Springer-Verlag, Berlin 1976. The present survey includes results from papers published after the copy deadline and recommends critically selected data. Furthermore, it comprises a bibliography of relevant literature. For each element, firstly data on binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility, solubility limit, dissociation pressure of compounds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas absorption and gas desorption kinetics, compound formation kinetics, precipitation kinetics, and property changes. Following the data on binary systems, the data of ternary systems are presented, beginning with systems which contain one metal and two gases or one gas and carbon and continuing with systems with two metals and one gas or carbon. (orig./GE)

  15. Trace metal speciation: Finally, correctly addressing trace metal issues

    International Nuclear Information System (INIS)

    Donard, O.F.X.

    2001-01-01

    The history of the development of trace metal speciation was discussed and the reasons behind the relatively slow widespread acceptance of its importance were presented. Partially, this was due to the lack of availability of commercial instrumentation and partly to the drive towards improving sensitivity in analytical chemistry which had focused attention on total concentration determinations. The sophistication and control of analytical instrumentation is now such that the spotlight must be turned onto the chemical species of an element present in a sample since this is what governs its behaviour in the biosphere. Indeed, several companies are currently considering the introduction of instrumentation specifically designed for metal species determination

  16. Emissions, activity data, and emission factors of fluorinated greenhouse gases (F-Gases) in Germany 1995-2002

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Winfried [Oeko-Recherche, Buero fuer Umweltforschung und -beratung GmbH, Frankfurt am Main (Germany)

    2005-06-15

    Before the 1997 Kyoto Protocol on Climate Protection, the fluorinated greenhouse gases HFCs, PFCs, and SF6 (F-gases) aroused little public attention. Since then, the standards on surveying and reporting on national emissions have been rising constantly. Amongst others, the annual reporting to the UNFCCC secretariat makes detailed declarations on use and emissions of F-gases necessary, which have to be filled in specified formats for submission (Common Reporting Format = CRF). The scientific basis has been set out by the UNFCCC guidelines on reporting, in accordance with the instructions laid down in IPCC good practice guidance. Additionally, in Germany the Centralised System of Emissions (ZSE) shall provide a suitable tool to satisfy any quality needs of both activity data and emission factors. From 1995 onwards, activity data and emissions of each individual application sector shall be presented in a comprehensible and transparent way. Therefore, the way of data collection as well as the estimation methods applied must be well documented. Moreover, data has to be prepared for appropriate importation into ZSE. It is the objective of this study to provide the transparency demanded within 40 national application sectors of F-gases, for the period between 1995 and 2002. - Firstly, all the activity data as well as the emissions related to them are presented and commented. This applies to manufacturing of products, F-gases banked in operating systems, and decommissioning. - Secondly, the methodologies applied to calculate the emissions are described and all sources of information are revealed, e.g. literature, names of experts from the manufacturing industry, users, trade, and academia. - Thirdly, reliability and safety of data are discussed. - Fourthly, possible deviations from the IPCC default values are stated and given reasons for. Wherever this intensive reviewing of 40 sectors through eight years of reporting uncovers gaps or inconsistencies in previous reports

  17. Atom trap trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O' Connor, T. P.; Young, L.

    2000-05-25

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

  18. Atom trap trace analysis

    International Nuclear Information System (INIS)

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O'Connor, T. P.; Young, L.

    2000-01-01

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual 85 Kr and 81 Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10 -11 and 10 -13 , respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications

  19. Primordial Noble Gases from Earth's Core

    Science.gov (United States)

    Wang, K.; Lu, X.; Brodholt, J. P.

    2016-12-01

    Recent partitioning experiment suggests helium is more compatible in iron melt than in molten silicates at high pressures (> 10 GPa) (1), thus provide the possibility of the core as being the primordial noble gases warehouse that is responsible for the high primordial/radiogenic noble gas isotopic ratios observed in plume-related basalts. However, the possible transportation mechanism of the noble gases from the core to the overlying mantle is still ambiguous, understanding how this process would affect the noble gas isotopic characteristics of the mantle is critical to validate this core reservoir model. As diffusion is a dominant mass transport process that plays an important role in chemical exchange at the core-mantle boundary (CMB), we have determined the diffusion coefficients of helium, neon and argon in major lower mantle minerals, i.e. periclase (MgO), bridgemanite (MgSiO3-Pv) and post-perovskite (MgSiO3-PPv), by first-principles calculation based on density functional theory (DFT). As expected, the diffusion rate of helium is the fastest at the CMB, which is in the range of 3 × 10-10 to 1 × 10-8 m2/s. The neon diffusion is slightly slower, from 5 × 10-10 to 5 × 10-9 m2/s. Argon diffuses slowest at the rate from 1 × 10-10 to 2 × 10-10 m2/s. We have further simulated the evolution of noble gas isotopic ratios in the mantle near the CMB. Considering its close relationship with the mantle plumes and very likely to be the direct source of "hot-spot" basalts, we took a close investigation on the large low-shear-velocity provinces (LLSVPs). Under reasonable assumptions based on our diffusion parameters, the modelling results indicate that LLSVP is capable of generating all the noble gas isotope signals, e.g., 3He/4He = 55 Ra, 3He/22Ne = 3.1, 3He/36Ar = 0.82, 40Ar/36Ar = 9500, that are in good agreement with the observed values in "hot-spot" basalts (2). Therefore, this core-reservior hypothesis is a self-consistent model that can fits in multiple noble gas

  20. Oscilloscope trace photograph digitizing system (TRACE)

    International Nuclear Information System (INIS)

    Richards, M.; Dabbs, R.D.

    1977-10-01

    The digitizing system allows digitization of photographs or sketches of waveforms and then the computer is used to reduce and analyze the data. The software allows for alignment, calibration, removal of baselines, removal of unwanted points and addition of new points which makes for a fairly versatile system as far as data reduction and manipulation are concerned. System considerations are introduced first to orient the potential user to the process of digitizing information. The start up and actual commands for TRACE are discussed. Detailed descriptions of each subroutine and program section are also provided. Three general examples of typical photographs are included. A partial listing of FAWTEK is made available. Once suitable arrays that contain the data are arranged, ''GO FA'' (active FAWTEK) and many mathematical operations to further analyze the data may be performed

  1. Subnanosecond breakdown in high-pressure gases

    Science.gov (United States)

    Naidis, George V.; Tarasenko, Victor F.; Babaeva, Natalia Yu; Lomaev, Mikhail I.

    2018-01-01

    Pulsed discharges in high-pressure gases are of considerable interest as sources of nonequilibrium plasma for various technological applications: pollution control, pumping of laser media, plasma-assisted combustion, etc. Recently, attention has been attracted to the use of subnanosecond voltage fronts, producing diffuse discharges with radii of several millimeters. Such plasma structures, similar to pulsed glow discharges, are of special interest for applications due to quasi-uniformity of plasma parameters in relatively large gas volumes. This review presents the results of experimental and computational study of subnanosecond diffuse discharge formation. A description of generators of short high-voltage pulses with subnanosecond fronts and of discharge setups is given. Diagnostic methods for the measurement of various discharge parameters with high temporal and spatial resolution are described. Obtained experimental data on plasma properties for a wide range of governing factors are discussed. A review of various theoretical approaches used for computational study of the dynamics and structure of fast ionization waves is given; the applicability of conventional fluid streamer models for simulation of subnanosecond ionization waves is discussed. Calculated spatial-temporal profiles of plasma parameters during streamer propagation are presented. The efficiency of subnanosecond discharges for the production of reactive species is evaluated. On the basis of the comparison of simulation results and experimental data the effects of various factors (voltage rise time, polarity, etc.) on discharge characteristics are revealed. The major physical phenomena governing the properties of subnanosecond breakdown are analyzed.

  2. Nozzle flow calculation for real gases

    International Nuclear Information System (INIS)

    Bier, K.; Ehrler, F.; Hartz, U.; Kissau, G.

    1977-01-01

    The flow of CHF 2 Cl vapor (refrigerant R 22) through a Laval nozzle of annular geometry has been investigated in the region near the saturation line with stagnation pressures up to 85 per cent of the critical pressure. Static pressure profiles measured along the nozzle axis were found in good agreement with profiles calculated for one-dimensional isentropic flow of the real gas the thermal properties of which were derived from an equation of state proposed previously by Rombusch. Minor deviations between measured and calculated static pressure curves occur in the supersonic part of the mozzle, especially when supersaturated states of the vapour are passed. These deviations can be attributed to uncertainties in the calculation of the enthalpy and to a small influence of the static pressure probe. An additional investigation was concerned with an approximate calculation of the nozzle flow of real gases. In this approximation the well known relations of ideal gas dynamics are applied, the ratio of specific heats for the ideal gas being replaced, however, by a suitably adapted isentropic exponent, which can be determined e.g. from measured values of the Laval pressure or of the mass flow. For pressure ratios p/po between 1 and approximately 0.1, corresponding to Mach numbers up to approximately 2.2, all the interesting properties of the investigated flow of CHF 2 Cl vapour are approximated within a few per cent. (orig.) [de

  3. Influence of the gray gases number in the weighted sum of gray gases model on the radiative heat exchange calculation inside pulverized coal-fired furnaces

    Directory of Open Access Journals (Sweden)

    Crnomarković Nenad Đ.

    2016-01-01

    Full Text Available The influence of the number of gray gases in the weighted sum in the gray gases model on the calculation of the radiative heat transfer is discussed in the paper. A computer code which solved the set of equations of the mathematical model describing the reactive two-phase turbulent flow with radiative heat exchange and with thermal equilibrium between phases inside the pulverized coal-fired furnace was used. Gas-phase radiative properties were determined by the simple gray gas model and two combinations of the weighted sum of the gray gases models: one gray gas plus a clear gas and two gray gases plus a clear gas. Investigation was carried out for two values of the total extinction coefficient of the dispersed phase, for the clean furnace walls and furnace walls covered by an ash layer deposit, and for three levels of the approximation accuracy of the weighting coefficients. The influence of the number of gray gases was analyzed through the relative differences of the wall fluxes, wall temperatures, medium temperatures, and heat transfer rate through all furnace walls. The investigation showed that there were conditions of the numerical investigations for which the relative differences of the variables describing the radiative heat exchange decrease with the increase in the number of gray gases. The results of this investigation show that if the weighted sum of the gray gases model is used, the complexity of the computer code and calculation time can be reduced by optimizing the number of gray gases. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in-house developed software tools

  4. Oxidative stress and pathogenic attack in plants, studied by laser based photoacoustic trace gas detection

    NARCIS (Netherlands)

    Santosa, Ignatius Edi

    2002-01-01

    Photoacoustic detection has proven to be a sensitive method, which is suitable for trace gas measurement. In this thesis, we improved the photoacoustic detection system to measure new biologically interesting gases, ethane (C2H6) and nitric oxide (NO). A new design of grating holder is incorporated

  5. Tracing Utopia in 'Utopia Station'

    DEFF Research Database (Denmark)

    Schwarzbart, Judith

    This paper will discuss how avant-garde rhetoric and working methods are used to rethink exhibition-making in the wake of the ‘relational aesthetics’ and visual art of the 90s. With Utopia Station curated by Molly Nesbit, Hans Ulrich Obrist, and Rirkrit Tiravanija as key example, we will look...... at the many layers of discourse, ‘thinking-in-process’ and collaboration. These processes led to particular presentational formats (display) and architectural frameworks for activities, and gave way to a variety of other material and situated performative modes of audience encounters. Here, we can trace avant...

  6. Queer Tracings of Genre

    DEFF Research Database (Denmark)

    Balle, Søren Hattesen

    as (re)tracings of genres that appear somehow residual or defunct in a post-modernist poetic context. On the other, they are made to "encode new [and queer, shb] meanings" (Anne Ferry) inasmuch as Ashbery, for instance, doubles and literalizes Dante's false etymology of the word ‘eclogue' (aig- and logos...

  7. The Trace of Superusers

    DEFF Research Database (Denmark)

    Samson, Kristine; Abasolo, José

    2013-01-01

    The city and its public spaces can be seen as a fragmented whole carrying meanings and traces of culture, use and politics with it. Whereas architects impose new stories and meanings on the urban fabric, the city itself is layered and assembled, a collective of social flows and routines a result ...

  8. Third order trace formula

    Indian Academy of Sciences (India)

    N. Centre for Advanced Scientific Research, Bangalore 560 064, India. 2Indian Institute of ... for rational functions φ with poles off R. In [5,16], Koplienko's trace formula was derived ... be a sequence of complex numbers such that ..... Again if we set the sum of the second and fourth term inside the integral in (2.3) to be. I2 ≡.

  9. Gases emissions of Green house Effect in Colombia

    International Nuclear Information System (INIS)

    Gonzalez B, Fabio

    1999-01-01

    Colombia when signing the agreement mark of the united nations for the global change in 1992 and to ratify it in 1996 committed, together with the other signatory countries, to elaborate and to publish national inventories of anthropogenic emissions of green house gases and plans for its reduction and control. In this reference mark a group of professionals inside the Colombian academy of exact, physical and natural sciences, began in July of 1995, the national inventory of greenhouse gases for Colombia, having the approval of the ministry of the environment, the financial support of the organization of German technical cooperation GTZ and the technical consultantship of the work group that it is carrying out the study in the case of Venezuela. This article presents a summary of the results of the project, making emphasis in the main anthropogenic activities responsible for these emissions, especially those related with the energetic sector

  10. Inhalation gases or gaseous mediators as neuroprotectants for cerebral ischaemia.

    Science.gov (United States)

    Sutherland, Brad A; Harrison, Joanne C; Nair, Shiva M; Sammut, Ivan A

    2013-01-01

    Ischaemic stroke is one of the leading causes of morbidity and mortality worldwide. While recombinant tissue plasminogen activator can be administered to produce thrombolysis and restore blood flow to the ischaemic brain, therapeutic benefit is only achieved in a fraction of the subset of patients eligible for fibrinolytic intervention. Neuroprotective therapies attempting to restrict the extent of brain injury following cerebral ischaemia have not been successfully translated into the clinic despite overwhelming pre-clinical evidence of neuroprotection. Therefore, an adequate treatment for the majority of acute ischaemic stroke patients remains elusive. In the stroke literature, the use of therapeutic gases has received relatively little attention. Gases such as hyperbaric and normobaric oxygen, xenon, hydrogen, helium and argon all possess biological effects that have shown to be neuroprotective in pre-clinical models of ischaemic stroke. There are significant advantages to using gases including their relative abundance, low cost and feasibility for administration, all of which make them ideal candidates for a translational therapy for stroke. In addition, modulating cellular gaseous mediators including nitric oxide, carbon monoxide, and hydrogen sulphide may be an attractive option for ischaemic stroke therapy. Inhalation of these gaseous mediators can also produce neuroprotection, but this strategy remains to be confirmed as a viable therapy for ischaemic stroke. This review highlights the neuroprotective potential of therapeutic gas therapy and modulation of gaseous mediators for ischaemic stroke. The therapeutic advantages of gaseous therapy offer new promising directions in breaking the translational barrier for ischaemic stroke.

  11. Noble gases and the early history of the Earth: Inappropriate paradigms and assumptions inhibit research and communication

    Science.gov (United States)

    Huss, G. R.; Alexander, E. C., Jr.

    1985-01-01

    The development of models as tracers of nobel gases through the Earth's evolution is discussed. A new set of paradigms embodying present knowledge was developed. Several important areas for future research are: (1) measurement of the elemental and isotopic compositions of the five noble gases in a large number of terrestrial materials, thus better defining the composition and distribution of terrestrial noble gases; (2) determinations of relative diffusive behavior, chemical behavior, and the distribution between solid and melt of noble gases under mantle conditions are urgently needed; (3) disequilibrium behavior in the nebula needs investigation, and the behavior of plasmas and possible cryotrapping on cold nebular solids are considered.

  12. Improved 206Pb/238U microprobe geochronology by the monitoring of a trace-element-related matrix effect; SHRIMP, ID-TIMS, ELA-ICP-MS and oxygen isotope documentation for a series of zircon standards

    Science.gov (United States)

    Black, L.P.; Kamo, S.L.; Allen, C.M.; Davis, D.W.; Aleinikoff, J.N.; Valley, J.W.; Mundil, R.; Campbell, I.H.; Korsch, R.J.; Williams, I.S.; Foudoulis, C.

    2004-01-01

    Precise isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) documentation is given for two new Palaeozoic zircon standards (TEMORA 2 and R33). These data, in combination with results for previously documented standards (AS3, SL13, QGNG and TEMORA 1), provide the basis for a detailed investigation of inconsistencies in 206Pb/238U ages measured by microprobe. Although these ages are normally consistent between any two standards, their relative age offsets are often different from those established by ID-TIMS. This is true for both sensitive high-resolution ion-microprobe (SHRIMP) and excimer laser ablation-inductively coupled plasma-mass spectrometry (ELA-ICP-MS) dating, although the age offsets are in the opposite sense for the two techniques. Various factors have been investigated for possible correlations with age bias, in an attempt to resolve why the accuracy of the method is worse than the indicated precision. Crystallographic orientation, position on the grain-mount and oxygen isotopic composition are unrelated to the bias. There are, however, striking correlations between the 206Pb/238U age offsets and P, Sm and, most particularly, Nd abundances in the zircons. Although these are not believed to be the primary cause of this apparent matrix effect, they indicate that ionisation of 206Pb/238U is influenced, at least in part, by a combination of trace elements. Nd is sufficiently representative of the controlling trace elements that it provides a quantitative means of correcting for the microprobe age bias. This approach has the potential to reduce age biases associated with different techniques, different instrumentation and different standards within and between laboratories. Crown Copyright ?? 2004 Published by Elsevier B.V. All rights reserved.

  13. Shale gases, a windfall for France?

    International Nuclear Information System (INIS)

    Tonnac, Alain de; Perves, Jean-Pierre

    2013-11-01

    After having recalled the definition and origin of shale gases, the different non conventional gases and their exploitation techniques (hydraulic fracturing and horizontal drilling) this report examines whether these gases are an opportunity for France. Some characteristics and data of the fossil and gas markets are presented and commented: world primary energy consumption, proved reserves of non conventional gases and their locations, European regions which may possess reserves of shale gases and coal-bed methane, origins of gas imports in France. The second part addresses shale gas deposits and their exploitation: discussion of the influence of the various rock parameters, evolution of production. The third part discusses the exploitation techniques and specific drilling tools. The issue of exploitation safety and security is addressed as well as the associated controversies: about the pollution of underground waters, about the fact that deep drillings result in pollution, about the risks associated with hydraulic fracturing and injections of chemical products, about the hold on ground and site degradation, about water consumption, about pollution due to gas pipeline leakage, about seismic risk, about noise drawbacks, about risks for health, about exploration and production authorization and license, and about air pollution and climate. The last part addresses the French situation and its future: status of the energy bill, recommendations made by a previous government, cancellation of authorizations, etc. Other information are provided in appendix about non conventional hydrocarbons, about shale gas exploitation in the USA, and about the Lacq gas

  14. Greenhouse gases study in Amazonia; Estudo de gases de efeito estufa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    D' Amelio, Monica Tais Siqueira

    2006-07-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO{sub 2} sources. The Amazon forest is a significant source of N{sub 2}O by soil process, and CH{sub 4} by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO{sub 2}, CH{sub 4}, CO, H{sub 2}, N{sub 2}O and SF{sub 6} have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO{sub 2} flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO{sub 2} flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H{sub 2} gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO{sub 2} sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that

  15. Greenhouse gases study in Amazonia; Estudo de gases de efeito estufa na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    D' Amelio, Monica Tais Siqueira

    2006-07-01

    The Amazon plays an important role on the global carbon cycle, as changing as carbon storage, since Amazon Basin is the biggest area of tropical forest, around 50% of global. Natural's process, deforestation, and use land are CO{sub 2} sources. The Amazon forest is a significant source of N{sub 2}O by soil process, and CH{sub 4} by anaerobic process like flooded areas, rice cultures, and others sources. This project is part of the LBA project (Large-Scale Biosphere Atmosphere Experiment in Amazonia), and this project is 'Vertical profiles of carbon dioxide and other trace gas species over the Amazon basin using small aircraft'. Since December 2000 vertical profiles of CO{sub 2}, CH{sub 4}, CO, H{sub 2}, N{sub 2}O and SF{sub 6} have been measured above central Amazonia. The local sampling was over Tapajos National Forest, a primary forest in Para State, where had a CO{sub 2} flux tower and an east impact area with sources like animals, rice cultivation, biomass burning, etc, to compare the influence of an impact area and a preserved area in the profiles. The Reserva Biologica de Cuieiras, at Amazon State, is the other studied place, where there already exists a CO{sub 2} flux tower, and an east preserved area at this State, to compare with the Cuieiras. The sampling has been carried out on vertical profile from 1000 ft up to 12000 ft using a semi-automated sampling package developed at GMD/NOAA and a small aircraft. The analysis uses the MAGICC system (Multiple Analysis of Gases Influence Climate Change) which is installed at the Atmospheric Chemistry Laboratory (LQA) in IPEN (Instituto de Pesquisas Energeticas e Nucleares). The results showed that all gases studied, except H{sub 2} gas, has been following the global trend. At the Para State, for the studied years, the Amazonian Forest performed as small CO{sub 2} sink. To compare Wet and Dry Seasons, subtracted the Ascension concentration values in the period to remove the global influence. So that, in the 2004 and

  16. Trace Elements in Cardiovascular Diseases

    Energy Technology Data Exchange (ETDEWEB)

    Masironi, R. [Cardiovascular Diseases Unit, World Health Organization, Geneva (Switzerland)

    1970-07-01

    Cardiovascular diseases are the leading cause of death in industrialized countries. Their incidence increases, apparently, as a, function of technological progress so that in the future they may become a major public health problem in developing countries too. Early diagnosis and prevention are the tools best suited to curb such an alarming trend, but our knowledge of these topics is unsatisfactory, Valuable information would be obtained through a systematic investigation of trace elements in relation to cardiovascular function and to various types of cardiovascular diseases. Such studies would provide clues to the following questions: 1. Why does the incidence and type of cardiovascular disease differ from one country to another? May this be related to differences in tissue mineral concentrations among various population groups? 2. Which trace elements if any are beneficial to cardiovascular health, and which are harmful ones that may act as aetiological agents for some cardiovascular diseases? 3. Is it possible to utilize measurements of mineral element concentration for diagnostic purposes in cardiovascular disease? (author)

  17. Geochemistry of mineral waters and associated gases of the Sakhalin Island (Far East of Russia)

    Science.gov (United States)

    Chelnokov, George A.; Bragin, Ivan V.; Kharitonova, Natalia A.

    2018-04-01

    Isotopic and chemical data on the mineral water, mud volcanoes fluid and associated gases from the biggest Russian island Sakhalin, together with previous stable isotope data (d18O, dD, 13C), allow elucidation of their origin and general evolution. The water fluid circulation is mainly related to marine environment inducing three distinct types: Na-HCO3-Cl alkali carbonate groundwaters, Na-Cl-HCO3 highly evolved saline and Na-Cl mature groundwaters, indicating different evolution. Chemical evolution of groundwater on Sakhalin Island demonstrated cation exchange and salinization as dominant evolutionary pathways. Isotopic composition of groundwaters varies from meteoric to metamorphic waters. These metamorphic waters consist of water hydration from the clay and seawater are traced in fluids of Yuzhno-Sakhalin mud volcano despite modification by mixing with meteoric waters and water-rock interaction processes. Fault systems that define the areas of highly mineralized water circulation appear to play a major role in the CO2 migration to the surface and CH4 generation. The δ13C(CO2) values have pointed that gas phase in high-pCO2 waters mostly consists of mantle-derived CO2. The carbon isotope signature of methane δ13C(CH4) and δD(CH4) indicates its distinct origin which is specified by tectonics. Methane manifestation in the south of the Sakhalin Island is mainly related to thermogenic reservoirs as they are more often dislocate by tectonics, and crossed by active and permeable faults. The sources of biogenous methane in the north of Sakhalin Island is related to younger and shallower reservoirs, and less affected by tectonic processes. The determinations of 222Rn have allowed observing that maximal radon flux is associated with high pCO2 waters.

  18. Density Fluctuations in Uniform Quantum Gases

    International Nuclear Information System (INIS)

    Bosse, J.; Pathak, K. N.; Singh, G. S.

    2011-01-01

    Analytical expressions are given for the static structure factor S(k) and the pair correlation function g(r) for uniform ideal Bose-Einstein and Fermi-Dirac gases for all temperatures. In the vicinity of Bose Einstein condensation (BEC) temperature, g(r) becomes long ranged and remains so in the condensed phase. In the dilute gas limit, g(r) of bosons and fermions do not coincide with Maxwell-Boltzmann gas but exhibit bunching and anti-bunching effect respectively. The width of these functions depends on the temperature and is scaled as √(inverse atomic mass). Our numerical results provide the precise quantitative values of suppression/increase (antibunching and bunching) of the density fluctuations at small distances in ideal quantum gases in qualitative agreement with the experimental observation for almost non-trapped dilute gases.

  19. Method of processing radioactive rare gase

    International Nuclear Information System (INIS)

    Tagusagawa, Atsushi; Tuda, Kazuaki.

    1988-01-01

    Purpose: To obtain a safety processing method without using mechanical pumps or pressure-proof containers and, accordingly, with no risk for the leakage of radioactive rare gas. Method: A container filled with zeolige is inserted with a cover being opened into an autoclave. Meanwhile, krypton-containing gases are supplied to an adsorption tower filled with adsorbents, cooled, adsorbed and then heated to desorb adsorbed krypton. The krypton-containing gases are introduced due to the pressure difference to the autoclave thereby causing krypton to adsorb at ambient temperature to zeolite. Then, the inside of the autoclave is heated to desorb krypton and adsorbed moistures from zeolite and the pressure is elevated. After sending the gases under pressure to the adsorption tower, the zeolite-filled container is taken out from the autoclave, tightly closed and then transferred to a predetermined site. (Takahashi, M.)

  20. Dark lump excitations in superfluid Fermi gases

    Science.gov (United States)

    Xu, Yan-Xia; Duan, Wen-Shan

    2012-11-01

    We study the linear and nonlinear properties of two-dimensional matter-wave pulses in disk-shaped superfluid Fermi gases. A Kadomtsev—Petviashvili I (KPI) solitary wave has been realized for superfluid Fermi gases in the limited cases of Bardeen—Cooper—Schrieffer (BCS) regime, Bose—Einstein condensate (BEC) regime, and unitarity regime. One-lump solution as well as one-line soliton solutions for the KPI equation are obtained, and two-line soliton solutions with the same amplitude are also studied in the limited cases. The dependence of the lump propagating velocity and the sound speed of two-dimensional superfluid Fermi gases on the interaction parameter are investigated for the limited cases of BEC and unitarity.

  1. Dark lump excitations in superfluid Fermi gases

    International Nuclear Information System (INIS)

    Xu Yan-Xia; Duan Wen-Shan

    2012-01-01

    We study the linear and nonlinear properties of two-dimensional matter-wave pulses in disk-shaped superfluid Fermi gases. A Kadomtsev—Petviashvili I (KPI) solitary wave has been realized for superfluid Fermi gases in the limited cases of Bardeen—Cooper—Schrieffer (BCS) regime, Bose—Einstein condensate (BEC) regime, and unitarity regime. One-lump solution as well as one-line soliton solutions for the KPI equation are obtained, and two-line soliton solutions with the same amplitude are also studied in the limited cases. The dependence of the lump propagating velocity and the sound speed of two-dimensional superfluid Fermi gases on the interaction parameter are investigated for the limited cases of BEC and unitarity

  2. Software trace cache

    OpenAIRE

    Ramírez Bellido, Alejandro; Larriba Pey, Josep; Valero Cortés, Mateo

    2005-01-01

    We explore the use of compiler optimizations, which optimize the layout of instructions in memory. The target is to enable the code to make better use of the underlying hardware resources regardless of the specific details of the processor/architecture in order to increase fetch performance. The Software Trace Cache (STC) is a code layout algorithm with a broader target than previous layout optimizations. We target not only an improvement in the instruction cache hit rate, but also an increas...

  3. Preconcentration of trace elements

    International Nuclear Information System (INIS)

    Zolotov, Yu. A.; Kuz'min, N.M.

    1990-01-01

    This monograph deals with the theory and practical applications of trace metals preconcentration. It gives general characteristics of the process and describes in detail the methods of preconcentration: solvent extraction, sorption, co-precipitation, volatilization, and others. Special attention is given to preconcentration in combination with subsequent determination methods. The use of preconcentration in analysis of environmental and biological samples, mineral raw materials, high purity substances, and various industrial materials is also considered

  4. Trace elements levels in centenarian ‘dodgers’

    OpenAIRE

    Alis, Rafael; Santos-Lozano, Alejandro; Sanchís-Gomar, Fabián; Pareja Galeano, Helios; Fiuza Luces, María del Carmen; Garatachea, Nuria; Lucía Mulas, Alejandro; Emanuele, Enzo

    2016-01-01

    Trace element bioavailability can play a role in several metabolic and physiological pathways known to be altered during the aging process. We aimed to explore the association of trace elements with increased lifespan by analyzing the circulating levels of seven trace elements (Cr, Cu, Fe, Mn, Mo, Se and Zn) in a cohort of healthy centenarians or ‘dodgers’ (≥100 years, free of major age-related diseases) in comparison with sex-matched younger elderly controls. Centenarians showed significant ...

  5. Experience with high-temperature filtration of incinerator flue gases

    International Nuclear Information System (INIS)

    Carpentier, S.; de Tassigny, C.

    1990-01-01

    It is always preferable to filter incinerator flue gases as close as possible to their origin, i.e. in a high-temperature zone, and means must be provided to destroy the other organic parts of the flyash resulting from these gases by in-filter combustion. The filter also traps a mineral part of the flyash, which eventually causes clogging and requires replacement or regeneration. Such filtration systems are available and can be operated on an industrial scale. They include candles made of micro-expanded refractory alloys supporting filtering media, porous ceramic candles and other devices. Research and subsequent pilot facility testing have enabled development of alumina fiber filter cartridges that offer more advantages than other equipment employed to date. Specifically, these advantages are: ultralight weight, which enables construction of systems that are relatively unaffected by creep and high-temperature deformations; excellent refractory qualities, which permit a use above 1000 degrees C; insensitivity to thermal shocks and in-situ carbon fines combustion capability; anti-acid quality of the material, which enables high-temperature filtration of acidic flue gases (chlorine and hydrochloric acid, SO x , etc.); low initial pressure drop of the cartridges; dimensional stability of the cartridges, which can be machined to a given tolerance with specific contours after casting and drying. This paper reports the results obtained during the last filtration system test campaign. Details are given for operating conditions, grain sizes and real-time monitoring of various parameters

  6. Bose-Einstein condensation in atomic alkali gases

    Science.gov (United States)

    Dodd, Robert J.

    1998-05-01

    I present a review of the time-independent Gross-Pitaevskii (GP), Bogoliubov, and finite-temperature Hartree-Fock-Bogoliubov (HFB) mean-field theories used to study trapped, Bose-Einstein condensed alkali gases. Numerical solutions of the (zero-temperature) GP equation are presented for attractive (negative scattering length) and repulsive (positive scattering length) interactions. Comparison is made with the Thomas-Fermi and (variational) trial wavefunction appr oximations that are used in the literature to study condensed gases. Numerical calculations of the (zero-temperature) Bogoliubov quasi-particle excitation frequencies are found to be in excellent agreement with the experimental results. The finite-temperature properties of condensed gases are examined using the Popov approximation (of the HFB theory) and a simple two-gas model. Specific, quantitative comparisons are made with experimental results for finite-temperature excitation frequencies. Qualitative comparisons are made between the results of the Popov approximation, two-gas model, and other published models for condensate fraction and thermal density distribution. The time-independent mean-field theories are found to be in excellent agreement with experimental results at relatively low temperatures (high condensate fractions). However, at higher temperatures (and condensate fractions of less than 50%) there are significant discrepancies between experimental data and theoretical calculations. This work was undertaken at the University of Maryland at College Park and was supported in part by the National Science Foundation (PHY-9601261) and the U.S. Office of Naval Research.

  7. Release of gases from uranium metal at high temperatures

    International Nuclear Information System (INIS)

    Sayi, Y.S.; Ramanjaneyulu, P.S.; Yadav, C.S.; Shankaran, P.S.; Chhapru, G.C.; Ramakumar, K.L.; Venugopal, V.

    2008-01-01

    Depending on the ambient environmental conditions, different gaseous species could get entrapped in uranium metal ingots or pellets. On heating, melting or vapourising uranium metal, these get released and depending on the composition, may cause detrimental effects either within the metal matrix itself or on the surrounding materials/environment. For instance, these gases may affect the performance of the uranium metal, which is used as fuel in the heavy water moderated research reactors, CIRUS and DHRUVA. Hence, detailed investigations have been carried out on the release of gases over a temperature range 875-1500 K employing hot vacuum extraction technique, in specimen uranium pellets made from uranium rods/ingots. Employing an on-line quadrupole mass spectrometer, the analysis of released gases was carried out. The isobaric interference between carbon monoxide and nitrogen at m/e = 28 in the mass spectrometric analysis has been resolved by considering their fragmentation patterns. Since no standards are available to evaluate the results, only the reproducibility is tested. The precision (relative standard deviation at 3σ level) of the method is ±5%. The minimum detectable gas content employing the method is 5.00 x 10 -09 m 3 . About 4 x 10 -04 m 3 /kg of gas is released from uranium pellets, with hydrogen as the main constituent. The gas content increases with storage in air

  8. Anisotropic ray trace

    Science.gov (United States)

    Lam, Wai Sze Tiffany

    Optical components made of anisotropic materials, such as crystal polarizers and crystal waveplates, are widely used in many complex optical system, such as display systems, microlithography, biomedical imaging and many other optical systems, and induce more complex aberrations than optical components made of isotropic materials. The goal of this dissertation is to accurately simulate the performance of optical systems with anisotropic materials using polarization ray trace. This work extends the polarization ray tracing calculus to incorporate ray tracing through anisotropic materials, including uniaxial, biaxial and optically active materials. The 3D polarization ray tracing calculus is an invaluable tool for analyzing polarization properties of an optical system. The 3x3 polarization ray tracing P matrix developed for anisotropic ray trace assists tracking the 3D polarization transformations along a ray path with series of surfaces in an optical system. To better represent the anisotropic light-matter interactions, the definition of the P matrix is generalized to incorporate not only the polarization change at a refraction/reflection interface, but also the induced optical phase accumulation as light propagates through the anisotropic medium. This enables realistic modeling of crystalline polarization elements, such as crystal waveplates and crystal polarizers. The wavefront and polarization aberrations of these anisotropic components are more complex than those of isotropic optical components and can be evaluated from the resultant P matrix for each eigen-wavefront as well as for the overall image. One incident ray refracting or reflecting into an anisotropic medium produces two eigenpolarizations or eigenmodes propagating in different directions. The associated ray parameters of these modes necessary for the anisotropic ray trace are described in Chapter 2. The algorithms to calculate the P matrix from these ray parameters are described in Chapter 3 for

  9. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  10. Gases and vacua handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 1: Gases and Vacua presents three major topics, which are the fourth to sixth parts of this volume. These topics are the remarks on units of physical quantities; kinetic theory of gases and gaseous flow; and theory of vacuum diffusion pumps. The first topic aims to present concisely the significance of units of physical quantities, catering the need and interest of those who take measurements and make calculations in different fields of vacuum sciences. The technique and applications of this particular topic are also provided. The second main topic focuses sp

  11. Origins of geothermal gases at Yellowstone

    Science.gov (United States)

    Lowenstern, Jacob B.; Bergfeld, Deborah; Evans, William C.; Hunt, Andrew G.

    2015-01-01

    Gas emissions at the Yellowstone Plateau Volcanic Field (YPVF) reflect open-system mixing of gas species originating from diverse rock types, magmas, and crustal fluids, all combined in varying proportions at different thermal areas. Gases are not necessarily in chemical equilibrium with the waters through which they vent, especially in acid sulfate terrain where bubbles stream through stagnant acid water. Gases in adjacent thermal areas often can be differentiated by isotopic and gas ratios, and cannot be tied to one another solely by shallow processes such as boiling-induced fractionation of a parent liquid. Instead, they inherit unique gas ratios (e.g., CH4/He) from the dominant rock reservoirs where they originate, some of which underlie the Quaternary volcanic rocks. Steam/gas ratios (essentially H2O/CO2) of Yellowstone fumaroles correlate with Ar/He and N2/CO2, strongly suggesting that H2O/CO2 is controlled by addition of steam boiled from water rich in atmospheric gases. Moreover, H2O/CO2 varies systematically with geographic location, such that boiling is more enhanced in some areas than others. The δ13C and 3He/CO2 of gases reflect a dominant mantle origin for CO2 in Yellowstone gas. The mantle signature is most evident at Mud Volcano, which hosts gases with the lowest H2O/CO2, lowest CH4 concentrations and highest He isotope ratios (~16Ra), consistent with either a young subsurface intrusion or less input of crustal and meteoric gas than any other location at Yellowstone. Across the YPVF, He isotope ratios (3He/4He) inversely vary with He concentrations, and reflect varied amounts of long- stored, radiogenic He added to the magmatic endmember within the crust. Similarly, addition of CH4 from organic-rich sediments is common in the eastern thermal areas at Yellowstone. Overall, Yellowstone gases reflect addition of deep, high-temperature magmatic gas (CO2-rich), lower-temperatures crustal gases (4He- and CH4-bearing), and those gases (N2, Ne, Ar) added

  12. Itinerant Ferromagnetism in Ultracold Fermi Gases

    DEFF Research Database (Denmark)

    Heiselberg, Henning

    2012-01-01

    Itinerant ferromagnetism in cold Fermi gases with repulsive interactions is studied applying the Jastrow-Slater approximation generalized to finite polarization and temperature. For two components at zero temperature a second order transition is found at akF ≃ 0.90 compatible with QMC. Thermodyna......Itinerant ferromagnetism in cold Fermi gases with repulsive interactions is studied applying the Jastrow-Slater approximation generalized to finite polarization and temperature. For two components at zero temperature a second order transition is found at akF ≃ 0.90 compatible with QMC...

  13. Flammability characteristics of combustible gases and vapors

    Energy Technology Data Exchange (ETDEWEB)

    Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)

    1964-05-01

    This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

  14. Investigations into electrical discharges in gases

    CERN Document Server

    Klyarfel'D, B N

    2013-01-01

    Investigations into Electrical Discharges in Gases is a compilation of scientific articles that covers the advances in the investigation of the fundamental processes occurring in electrical discharges in gases and vapors. The book details the different aspects of the whole life cycle of an arc, which include the initiation of a discharge, its transition into an arc, the lateral spread of the arc column, and the recovery of electric strength after extinction of an arc. The text also discusses the methods for the dynamic measurement of vapor density in the vicinity of electrical discharges, alon

  15. Nanoclusters and Microparticles in Gases and Vapors

    CERN Document Server

    Smirnov, Boris M

    2012-01-01

    Research of processes involving Nanoclusters and Microparticleshas been developing fastin many fields of rescent research, in particular in materials science. To stay at the cutting edge of this development, a sound understanding of the processes is needed. In this work, several processes involving small particles are described, such as transport processes in gases, charging of small particles in gases, chemical processes, atom attachment and quenching of excited atomic particles on surfaces, nucleation, coagulation, coalescence and growth processes for particles and aggregates. This work pres

  16. Ultracold Dipolar Gases in Optical Lattices

    OpenAIRE

    Trefzger, C.; Menotti, C.; Capogrosso-Sansone, B.; Lewenstein, M.

    2011-01-01

    This tutorial is a theoretical work, in which we study the physics of ultra-cold dipolar bosonic gases in optical lattices. Such gases consist of bosonic atoms or molecules that interact via dipolar forces, and that are cooled below the quantum degeneracy temperature, typically in the nK range. When such a degenerate quantum gas is loaded into an optical lattice produced by standing waves of laser light, new kinds of physical phenomena occur. These systems realize then extended Hubbard-type m...

  17. Emission of greenhouse gases from Danish agriculture

    International Nuclear Information System (INIS)

    Olesen, J.E.; Petersen, S.O.; Fenhann, J.V.; Andersen, J.M.; Jacobsen, B.H.

    2001-01-01

    emission factors for nitrous oxide does not imply a correspondingly large uncertainty in the relative contribution of individual sources to the total emission. The different sources of nitrous oxide in the field are affected by the same mechanisms independent of location, and thus the uncertainty is mainly associated with the level of this emission in Denmark compared with other regions. In Denmark there has not previously been any concerted research effort to quantify emissions of greenhouse gases from agriculture. The existing, somewhat scattered research has mainly been a spin-off from research programmes with other main objectives. Accordingly there is no solid foundation for evaluation of neither emission levels nor mitigation options. A proposal for a research programme on emission of greenhouse gases from agriculture is therefore presented, which should provide a better basis for quantifying individual emission sources, their development over time, and the effect of reduction measures. Emphasis is given to improve our knowledge on emissions of methane and nitrous oxide, and to the possibilities of agriculture in storing carbon and in the reduction and substitution of fossil fuel use. (au)

  18. Plasma processes including electron beam for off-gases purification

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Witman, S.; Licki, J.

    2011-01-01

    Complete text of publication follows. Non-thermal plasma technologies based on different methods of plasma generation are being applied for ozone generation for different applications, waste water and off-gases treatment. Plasmas create reactive species, in particular ions, radicals or other reactive compounds, which can decompose pollutant molecules, organic particulate matter or soot. Electron beam flue gas treatment is another plasma-based technology which has been successfully demonstrated on industrial scale coal fired power plants. High efficiency of SO 2 (> 95%) and NO x (> 70%) has been obtained and industrial plant applying this process has been built in Poland. The further investigations carried out all over the world have illustrated that the process can be applied for poly-aromatic hydrocarbons (PAH) destruction as well, and just recently research laboratories in the US and South Korea have reported in the feasibility of the process for mercury removal from the flue gas. The recent studies concern a new type of accelerators implementation in the industrial scale, application of the process in the high sulfur oil fired boilers and Diesel off - gases purification. The treatment of the flue gases with the high NOx concentration is a special challenge for the technology since the main energy consumption (and applied accelerators power) is related to this pollutant content in the processed off gases. The pulse beams and scavenger application can be a solution to reduce investment and operational costs. The further development of the technology is directly connected with high power accelerators development. Acknowledgement: The R and D activities are supported by the European Regional Development Found in the frame of the project PlasTEP 'Dissemination and fostering of plasma based technological innovation for environment protection in the Baltic Sea Region'.

  19. Screening on the differentially expressed miRNAs in zebrafish (Danio rerio) exposed to trace β-diketone antibiotics and their related functions

    International Nuclear Information System (INIS)

    Li, Jieyi; Liu, Jinfeng; Zhang, Yuhuan; Wang, Xuedong; Li, Weijun; Zhang, Hongqin; Wang, Huili

    2016-01-01

    Highlights: • DKAs possessed toxic effect transfer relation across larval and adult zebrafish. • 215 mature miRNAs were differentially expressed in three comparison groups. • A regulatory network for 4 positive miRNA genes (miR-10, −96, −92, −184) was plotted. • Expression of miR-184, −96, −10 and −92 was proved with miRNA-seq, qRT-PCR and ISH. • DKA exposure induced severe histopathological changes in zebrafish tissues. - Abstract: The toxicity of β-diketone antibiotics (DKAs) to larval and adult zebrafish (Danio rerio) was investigated by miRNA sequencing and bioinformatics analyses. In control and DKA-exposed groups, 215 differentially expressed miRNAs were screened, and 4076 differential target genes were predicted. Among 51 co-differentially expressed genes, 45 were annotated in KOG functional classification, and 34 in KEGG pathway analysis. The homology analysis of 20 miRNAs with human hsa-miRNAs demonstrated 17 high homologous sequences. The expression levels of 12 miRNAs by qRT-PCR were consistent with those by sRNA-seq. A regulatory network for 4 positive miRNA genes (dre-miR-10, −96, −92 and −184) was plotted, and the high-degree of connectivity between miRNA-gene pairs suggests that these miRNAs play critical roles during zebrafish development. The consistent expression of dre-miR-184 and dre-miR-96 was proved in 120-hpf zebrafish brain, gill, otoliths and lateral line neuromast by qRT-PCR, miRNA-seq, W-ISH and ISH. DKA-exposure led to vacuolation of interstitial cells, reduced number of neurons, glial cell proliferation and formation of glial scar, and the obvious abnormality of cell structure might result from abnormal expression of differentially expressed miRNAs. In general, chronic DKA-exposure resulted in comprehensively toxic effects on larval and adult zebrafish tissues, especially for nervous system.

  20. Screening on the differentially expressed miRNAs in zebrafish (Danio rerio) exposed to trace β-diketone antibiotics and their related functions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jieyi; Liu, Jinfeng; Zhang, Yuhuan [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China); Wang, Xuedong [Key Laboratory of Watershed Sciences and Health of Zhejiang Province, Wenzhou Medical University, Wenzhou 325035 (China); Li, Weijun [Puyang People’s Hospital of Henan Province, Puyang 457000 (China); Zhang, Hongqin [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China); Wang, Huili, E-mail: wxdong@wzmc.edu.cn [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China)

    2016-09-15

    Highlights: • DKAs possessed toxic effect transfer relation across larval and adult zebrafish. • 215 mature miRNAs were differentially expressed in three comparison groups. • A regulatory network for 4 positive miRNA genes (miR-10, −96, −92, −184) was plotted. • Expression of miR-184, −96, −10 and −92 was proved with miRNA-seq, qRT-PCR and ISH. • DKA exposure induced severe histopathological changes in zebrafish tissues. - Abstract: The toxicity of β-diketone antibiotics (DKAs) to larval and adult zebrafish (Danio rerio) was investigated by miRNA sequencing and bioinformatics analyses. In control and DKA-exposed groups, 215 differentially expressed miRNAs were screened, and 4076 differential target genes were predicted. Among 51 co-differentially expressed genes, 45 were annotated in KOG functional classification, and 34 in KEGG pathway analysis. The homology analysis of 20 miRNAs with human hsa-miRNAs demonstrated 17 high homologous sequences. The expression levels of 12 miRNAs by qRT-PCR were consistent with those by sRNA-seq. A regulatory network for 4 positive miRNA genes (dre-miR-10, −96, −92 and −184) was plotted, and the high-degree of connectivity between miRNA-gene pairs suggests that these miRNAs play critical roles during zebrafish development. The consistent expression of dre-miR-184 and dre-miR-96 was proved in 120-hpf zebrafish brain, gill, otoliths and lateral line neuromast by qRT-PCR, miRNA-seq, W-ISH and ISH. DKA-exposure led to vacuolation of interstitial cells, reduced number of neurons, glial cell proliferation and formation of glial scar, and the obvious abnormality of cell structure might result from abnormal expression of differentially expressed miRNAs. In general, chronic DKA-exposure resulted in comprehensively toxic effects on larval and adult zebrafish tissues, especially for nervous system.

  1. Processes to remove acid forming gases from exhaust gases

    Science.gov (United States)

    Chang, S.G.

    1994-09-20

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO[sub 2]; (B) contacting the gas sample of step (A) comprising NO[sub 2] with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0 and 100 C at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environmentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed. 16 figs.

  2. Biogenic, biomass and biofuel sources of trace gases in southern Africa

    CSIR Research Space (South Africa)

    Otter, LB

    2001-03-01

    Full Text Available Biogenic processes in southern African savannas are estimated to produce 1.0 Tg NO yr(-1), 44.2-87.8 Tg C yr(-1) as non-methane hydrocarbons (NMHCs) and to consume 0.23 Tg CH4 yr(-1). Floodplains and wetlands in southern Africa are estimated...

  3. Distribution of trace gases and aerosols in the troposphere over West Siberia and Kara Sea

    Science.gov (United States)

    Belan, Boris D.; Arshinov, Mikhail Yu.; Paris, Jean-Daniel; Nédélec, Philippe; Ancellet, Gérard; Pelon, Jacques; Berchet, Antoine; Arzoumanian, Emmanuel; Belan, Sergey B.; Penner, Johannes E.; Balin, Yurii S.; Kokhanenko, Grigorii; Davydov, Denis K.; Ivlev, Georgii A.; Kozlov, Artem V.; Kozlov, Alexander S.; Chernov, Dmitrii G.; Fofonov, Alexader V.; Simonenkov, Denis V.; Tolmachev, Gennadii

    2015-04-01

    The Arctic is affected by climate change much stronger than other regions of the globe. Permafrost thawing can lead to additional methane release, which enhances the greenhouse effect and warming, as well as changes of Arctic tundra ecosystems. A great part of Siberian Arctic is still unexplored. Ground-based investigations are difficult to be carried out in this area due to it is an out-of-the-way place. So, in spite of the high cost, aircraft-based in-situ measurements can provide a good opportunity to fill up the gap in data on the atmospheric composition over this region. The ninth YAK-AEROSIB campaign was focused on the airborne survey of Arctic regions of West Siberia. It was performed in October 2014. During the campaign, the high-precision in-situ measurements of CO2, CH4, CO, O3, black carbon and aerososls, including aerosol lidar profiles, have been carried out in the Siberian troposphere from Novosibirsk to Kara Sea. Vertical distributions of the above atmospheric constituents will be presented. This work was supported by LIA YAK-AEROSIB, CNRS (France), the French Ministry of Foreign Affairs, CEA (France), the Branch of Geology, Geophysics and Mining Sciences of RAS (Program No. 5); State contracts of the Ministry of Education and Science of Russia No. 14.604.21.0100, (RFMTFIBBB210290) and No. 14.613.21.0013 (RFMEFI61314X0013); Interdisciplinary integration projects of the Siberian Branch of the Russian Academy of Science No. 35, No. 70 and No. 131; and Russian Foundation for Basic Research (grants No. 14-05-00526 and 14-05-00590).

  4. Tracing ancient hydrogeological fracture network age and compartmentalisation using noble gases

    Science.gov (United States)

    Warr, Oliver; Sherwood Lollar, Barbara; Fellowes, Jonathan; Sutcliffe, Chelsea N.; McDermott, Jill M.; Holland, Greg; Mabry, Jennifer C.; Ballentine, Christopher J.

    2018-02-01

    We show that fluid volumes residing within the Precambrian crystalline basement account for ca 30% of the total groundwater inventory of the Earth (> 30 million km3). The residence times and scientific importance of this groundwater are only now receiving attention with ancient fracture fluids identified in Canada and South Africa showing: (1) microbial life which has existed in isolation for millions of years; (2) significant hydrogen and hydrocarbon production via water-rock reactions; and (3) preserving noble gas components from the early atmosphere. Noble gas (He, Ne, Ar, Kr, Xe) abundance and isotopic compositions provide the primary evidence for fluid mean residence time (MRT). Here we extend the noble gas data from the Kidd Creek Mine in Timmins Ontario Canada, a volcanogenic massive sulfide (VMS) deposit formed at 2.7 Ga, in which fracture fluids with MRTs of 1.1-1.7 Ga were identified at 2.4 km depth (Holland et al., 2013); to fracture fluids at 2.9 km depth. We compare here the Kidd Creek Mine study with noble gas compositions determined in fracture fluids taken from two mines (Mine 1 & Mine 2) at 1.7 and 1.4 km depth below surface in the Sudbury Basin formed by a meteorite impact at 1.849 Ga. The 2.9 km samples at Kidd Creek Mine show the highest radiogenic isotopic ratios observed to date in free fluids (e.g. 21Ne/22Ne = 0.6 and 40Ar/36Ar = 102,000) and have MRTs of 1.0-2.2 Ga. In contrast, resampled 2.4 km fluids indicated a less ancient MRT (0.2-0.6 Ga) compared with the previous study (1.1-1.7 Ga). This is consistent with a change in the age distribution of fluids feeding the fractures as they drain, with a decreasing proportion of the most ancient end-member fluids. 129Xe/136Xe ratios for these fluids confirm that boreholes at 2.4 km versus 2.9 km are sourced from hydrogeologically distinct systems. In contrast, results for the Sudbury mines have MRTs of 0.2-0.6 and 0.2-0.9 Ga for Mines 1 and 2 respectively. While still old compared to almost all groundwaters reported in the literature to date, these younger residence times compared to Kidd Creek Mine are consistent with significant fracturing created by the impact event, facilitating more hydrogeologic connection and mixing of fluids in the basin. In all samples from both Kidd Creek Mine and Sudbury, a 124-128Xe excess is identified over modern air values. This is attributed to an early atmospheric xenon component, previously identified at Kidd Creek Mine but which has to date not been observed in fluids with a residence time as recent as 0.2-0.6 Ga. The temporal and spatial sampling at Kidd Creek Mine is also used to verify our proposed conceptual model which provides key constraints regarding distribution, volumes and residence times of fracture fluids on the smaller, regional, scale.

  5. South African EUCAARI measurements: Seasonal variation of trace gases and aerosol optical properties

    NARCIS (Netherlands)

    Laakso, L.; Vakkari, V.; Virkkula, A.; Laakso, H.; Backman, J.; Kulmala, M.; Beukes, J.P.; Zyl, P.G. van; Tiitta, P.; Josipovic, M.; Pienaar, J.J.; Chiloane, K.; Gilardoni, S.; Vignati, E.; Wiedensohler, A.; Tuch, T.; Birmili, W.; Piketh, S.; Collett, K.; Fourie, G.D.; Komppula, M.; Lihavainen, H.; Leeuw, G. de; Kerminen, V.-M.

    2012-01-01

    In this paper we introduce new in situ observations of atmospheric aerosols, especially chemical composition, physical and optical properties, on the eastern brink of the heavily polluted Highveld area in South Africa. During the observation period between 11 February 2009 and 31 January 2011, the

  6. Changes of the climate induced by trace gases. Current state of research

    Energy Technology Data Exchange (ETDEWEB)

    Grassl, H

    1987-02-01

    Any attempt of predicting climatic changes is a very different task, because it requires good insight into and knowledge of a complex system whose components respond very differently in terms of time. Hence there remain many uncertainties in efforts towards 'predicting' climatic changes considering the enhancing greenhouse effect. As with all environmental problems, the best reaction is to conserve resources, and systematically explore the interactions. Reducing the CO/sub 2/, for instance, will be highly awarded. (orig./HSCH).

  7. Observing Trace Gases Of The Arctic And Subarctic Stratosphere By TELIS

    Science.gov (United States)

    Xu, Jian; Schreier, Franz; Doicu, Adrian; Vogt, Peter; Birk, Manfred; Wagner, Georg; Trautmann, Thomas

    2013-12-01

    The Terahertz and submillimeter Limb Sounder (TELIS) is a balloon-borne cryogenic heterodyne spectrometer developed by a consortium of European institutes, which was mounted together with the Michelson Interferometer for Passive Atmospheric Sounding - Balloon (MIPAS- B) and the mini- Differential Optical Absorption Spectroscopy (mini-DOAS) instruments on a stratospheric gondola. The TELIS instrument is designed to monitor the vertical distribution of stratospheric state parameters associated with ozone destruction and climate change in Arctic and subarctic areas. The broad spectral coverage of TELIS is achieved by utilizing three frequency channels: a tunable 1.8THz channel based on a solid state local oscillator and a hot electron bolometer as mixer, a 480-650GHz channel with the Superconducting Integrated Receiver (SIR) technology, and a highly compact 500 GHz channel developed by the German Aerospace Center (DLR), the Netherlands Institute for Space Research (SRON), and the Rutherford Apple- ton Laboratory (RAL), respectively. Furthermore, an ex- tended spectral range is observed by the combination of TELIS and MIPAS-B, which can be employed for cross validation of several gas concentrations. Between 2009 and 2011 three successful scientific flights have been launched in Kiruna, Sweden and all relevant atmospheric gas species were seen by TELIS over an altitude range of 10-32.5 km. For estimation of concentration profiles from TELIS measurements, a constrained nonlinear least squares fitting framework along with var- ious Tikhonov-type regularization methods has been developed. In this work we present recent retrieval results from latest calibrated spectra during the 2010 flight. Emphasis is placed on ozone (O3) and hydrogen chloride (HCl), and error issues pertaining to the main instrumental uncertainty terms including nonlinearity in the calibration procedure, sideband ratio and pointing offset are investigated. The retrieved profiles are validated against other limb sounding instruments, e.g. the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES), the Microwave Limb Sounder (MLS), and MIPAS-B.

  8. Tropospheric methane in northern Finland: seasonal variations, transport patterns and correlations with other trace gases

    International Nuclear Information System (INIS)

    Aalto, Tuula; Hatakka, Juha; Lallo, Marko

    2007-01-01

    Methane mixing ratios have been continuously observed at Pallas, Finland since winter 2004. The seasonal variation in monthly means was ca. 40 ppb, showing largest mixing ratios in winter and also high values during late summer. Examination of back-trajectories showed that the air masses with elevated methane mixing ratios arrived from continental Eastern and Central Europe while low methane mixing ratios were connected with Atlantic and Arctic air masses. During summer, air masses with highest mixing ratios arrived from Northwestern Russia indicating wetland sources, while the influence of southern emissions became more significant in winter. Methane was positively correlated with carbon dioxide and negatively correlated with ozone in winter. The average slope of the selected wintertime background hourly mean mixing ratios was 7.0 ± 1.2 ppb(CH 4 )/ppm(CO 2 ). Nocturnal summertime low-altitude measurements above a local wetland source indicated slopes of about 10 ± 1 ppb(CH 4 )/ppm(CO 2 ). The different slopes reflect the differences in emission parameters

  9. Variations of trace gases over the Bay of Bengal during the summer ...

    Indian Academy of Sciences (India)

    I A Girach

    2018-02-16

    Feb 16, 2018 ... Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, 55128 Mainz, Germany. 3 ... fossil fuel and biomass burning supplemented with oxidation of ... About 90% of CH4 is removed through its reaction.

  10. Analysis of Atmospheric Mercury and Associated Trace Gases in Dallas Fort Worth, TX (Barnett Shale area)

    Science.gov (United States)

    Laine, P. L.; Talbot, R. W.; Lefer, B. L.; Flynn, J. H.

    2012-12-01

    Throughout the month of June 2011, a variety of air quality measurements were obtained in the Dallas Fort Worth (Barnett Shale) field campaign. Species such as Hg0, O3, CO, NO, NO2, SO2 were monitored continuously along with a variety of volatile organic carbon (VOC) species ranging in size from C2 (ethane) to C9 aromatics to sesquiterpines. Mixed layer boundary heights were also monitored by Ceilometer measurements. At first glance, the mercury data has peaks that reach as high as 750 ppqv (parts per quadrillion by volume) which is approximately a 5 fold increase over the typical background values observed (~ 150 ppqv). The Fort Worth area has underlying Barnett Shale with thousands of natural gas compressor stations scattered throughout the surrounding landscape. We believe that a potential source of the elevated Hg0 is the result of leakage from these stations under the nocturnal boundary layer. A closer look at diurnal variations and backward wind trajectories will yield information pertaining to the types of air masses spanning the area. We will utilize the suite of chemical and meteorological measurements conducted during the campaign to facilitate source identification for specific time periods. Analysis of these data should provide new information on as yet unexplored sources of atmospheric mercury.

  11. Observations of trace gases and aerosols over the Indian Ocean during the monsoon transition period

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, T.K.; Khan, A.; Ahammed, Y.N.; Tanwar, R.S.; Parmar, R.S.; Zalpuri, K.S.; Gupta, P.K.; Jain, S.L.; Singh, R.; Mitra, A.P.; Garg, S.C.; Suryanarayana, A.; Murty, V.S.N.; DileepKumar, M.; Shepherd, A.J.

    the NOAA-CIRES Climate Diagnostics Center for the reanalysis data provided at their website at http://www.cdc.noaa.gov/. This is NIO contribu- tion no. 4143. References Bange H W, Ramesh R, Rapsomanikis S and Andreae M O 1998 Methane in surface waters...

  12. Airborne Observations of Ozone and Other Trace Gases Upwind of National Parks in California and Nevada

    Science.gov (United States)

    Iraci, Laura T.

    2016-01-01

    The Alpha Jet Atmospheric eXperiment (AJAX) is a research project based at Moffett Field, CA, which collects airborne measurements of ozone, carbon dioxide, methane, water vapor, and formaldehyde, as well as 3-D winds, temperature, pressure, and location. Since its first science flight in 2011, AJAX has developed a wide a variety of mission types, combining vertical profiles (from approximately 8 km to near surface), boundary layer legs, and plume sampling as needed. With an ongoing five-year data set, the team has sampled over 160 vertical profiles, a dozen wildfires, and numerous stratospheric ozone intrusions. Our largest data collection includes 55 vertical profiles at Railroad Valley, NV, approximately 100 miles southwest of Great Basin National Park, and many of those flights include comparisons to surface monitors in the Nevada Rural Ozone Initiative network. We have also collected a smaller set of measurements northwest of Joshua Tree National Park, and are looking to develop partnerships that can put this data to use to assess or improve air quality in nearby Parks. AJAX also studies the plumes emitted by wildfires in California, as most emissions inventories are based on prescribed fires. We have sampled a dozen fires, and results will be presented from several, including the Rim (2013), Soberanes and Cedar (2016) Fires.

  13. Evolution of Trace Gases and Particles Emitted by a Chaparral Fire in California

    Science.gov (United States)

    2012-02-07

    measurements in BB plumes and concluded that O3 formation is ubiquitous in tropical BB plumes, but O3 formation or destruction can oc- cur in extratropical BB...the Aventech AIMMS20AQ air- borne probe for turbulence measurements during the Convective Storm Initiation Project, Atmos. Chem. Phys., 8, 5449–5463

  14. Ultrafast-Laser-Induced Backward Stimulated Raman Scattering for Tracing Atmospheric Gases

    Directory of Open Access Journals (Sweden)

    Zheltiko A.

    2013-03-01

    Full Text Available By combining tunable broadband pulse generation with nonlinear spectral compression, we demonstrate a prototype scheme for highly selective coherent standoff sensing of air molecules and discuss its coupling to the recently demonstrated backward atmospheric lasing.

  15. The heterogeneous interaction of trace gases on mineral dust and soot: kinetics and mechanism

    OpenAIRE

    Karagulian, Federico; Rossi, Michel

    2007-01-01

    The present thesis work deals with the investigation of the heterogeneous reactions involving nitrate radical (NO3), dinitrogen pentoxide (N2O5) and ozone (O3) on surrogates of atmospheric mineral dust particles characteristic of the troposphere. An additional investigation of heterogeneous reaction of NO3 on flame soot was carried out. The goal is to characterize the kinetics (the uptake coefficient γ) as well as the reaction products. The obtained results are intended to provide reliable da...

  16. Zinc: a multipurpose trace element

    Energy Technology Data Exchange (ETDEWEB)

    Stefanidou, M.; Maravelias, C.; Dona, A.; Spiliopoulou, C. [University of Athens, Department of Forensic Medicine and Toxicology, Athens (Greece)

    2006-01-01

    Zinc (Zn) is one of the most important trace elements in the body and it is essential as a catalytic, structural and regulatory ion. It is involved in homeostasis, in immune responses, in oxidative stress, in apoptosis and in ageing. Zinc-binding proteins (metallothioneins, MTs), are protective in situations of stress and in situations of exposure to toxic metals, infections and low Zn nutrition. Metallothioneins play a key role in Zn-related cell homeostasis due to their high affinity for Zn, which is in turn relevant against oxidative stress and immune responses, including natural killer (NK) cell activity and ageing, since NK activity and Zn ion bioavailability decrease in ageing. Physiological supplementation of Zn in ageing and in age-related degenerative diseases corrects immune defects, reduces infection relapse and prevents ageing. Zinc is not stored in the body and excess intakes result in reduced absorption and increased excretion. Nevertheless, there are cases of acute and chronic Zn poisoning. (orig.)

  17. A new multi-gas constrained model of trace gas non-homogeneous transport in firn: evaluation and behaviour at eleven polar sites

    Directory of Open Access Journals (Sweden)

    E. Witrant

    2012-12-01

    Full Text Available Insoluble trace gases are trapped in polar ice at the firn-ice transition, at approximately 50 to 100 m below the surface, depending primarily on the site temperature and snow accumulation. Models of trace gas transport in polar firn are used to relate firn air and ice core records of trace gases to their atmospheric history. We propose a new model based on the following contributions. First, the firn air transport model is revised in a poromechanics framework with emphasis on the non-homogeneous properties and the treatment of gravitational settling. We then derive a nonlinear least square multi-gas optimisation scheme to calculate the effective firn diffusivity (automatic diffusivity tuning. The improvements gained by the multi-gas approach are investigated (up to ten gases for a single site are included in the optimisation process. We apply the model to four Arctic (Devon Island, NEEM, North GRIP, Summit and seven Antarctic (DE08, Berkner Island, Siple Dome, Dronning Maud Land, South Pole, Dome C, Vostok sites and calculate their respective depth-dependent diffusivity profiles. Among these different sites, a relationship is inferred between the snow accumulation rate and an increasing thickness of the lock-in zone defined from the isotopic composition of molecular nitrogen in firn air (denoted δ15N. It is associated with a reduced diffusivity value and an increased ratio of advective to diffusive flux in deep firn, which is particularly important at high accumulation rate sites. This has implications for the understanding of δ15N of N2 records in ice cores, in relation with past variations of the snow accumulation rate. As the snow accumulation rate is clearly a primary control on the thickness of the lock-in zone, our new approach that allows for the estimation of the lock-in zone width as a function of accumulation may lead to a better constraint on the age difference between the ice and entrapped gases.

  18. Analysis the mixtures of polyphenyls by gas chromatrogaphie. 1.- Area response for biphenyl and terphenyls relative to triphenylmethane; Analisis de polifenilos por cromatografia de gases 1.- Respuesta relativa del bifenilo y terfenilos respecto al trifenilmetano

    Energy Technology Data Exchange (ETDEWEB)

    Perez Garcia, M

    1966-07-01

    The relative performances of the thermal conductivity and flame ionization detectors towards triphenylmethane were investigated for each one of the components of biphenyl of biphenyl and terphenyl mixtures. The influence of the concentration of the considered compound as well as the influence derived from the present of all other components on the above-mentioned relative performance were studied. A 2 m long column filled with 50-70 mesh stomacher containing 20% apiezon L was used to carry out the study with the thermal conductivity detector by keeping the column at 300 degree centigree using helium gas as carrier. (Author) 13 refs.

  19. Application of copper sulfate pentahydrate as an ammonia removal reagent for the determination of trace impurities in ammonia by gas chromatography.

    Science.gov (United States)

    Aomura, Yoko; Kobayashi, Yoshihiko; Miyazawa, Yuzuru; Shimizu, Hideharu

    2010-03-12

    Rapid analysis of trace permanent gas impurities in high purity ammonia gas for the microelectronics industry is described, using a gas chromatograph equipped with a phtoionization detector. Our system incorporates a reactive precolumn in combination with the analytical column to remove the ammonia matrix peak that otherwise would complicate the measurements due to baseline fluctuations and loss of analytes. The performance of 21 precolumn candidate materials was evaluated. Copper sulfate pentahydrate (CuSO(4).5H(2)O) was shown to selectively react with ammonia at room temperature and atmospheric column pressures, without affecting the hydrogen, oxygen, nitrogen, methane or carbon monoxide peak areas. To prevent loss of trace carbon dioxide, an additional boron trioxide reactant layer was inserted above the copper sulfate pentahydrate bed in the reactive precolumn. Using the combined materials, calibration curves for carbon dioxide proved to be equivalent in both ammonia and helium matrix gases. These curves were equivalent in both matrix gases. The quantitative performance of the system was also evaluated. Peak repeatabilities, based on eight injections, were in the range of 4.1-8.2% relative standard deviation; and detection limits were 6.9 ppb for H(2), 1.8 ppb for O(2), 1.6 ppb for N(2), 6.4 ppb for CH(4), 13 ppb for CO, and 5.4 ppb for CO(2). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  20. Isotope aided studies of atmospheric carbon dioxide and other greenhouse gases. Phase II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    The substantial increase in atmospheric greenhouse gas concentrations and their role in global warming have become major concerns of world governments. Application of isotope techniques to label sources and sinks of CO{sub 2} and other greenhouse gases has emerged as a potentially powerful method for reducing uncertainties in the global CO{sub 2} budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. As with CO{sub 2} concentration measurements, meaningful integration of isotopes in global models requires careful attention to quality assurance, quality control and inter-comparability of measurements made by a number of networks and laboratories. To support improvements in isotope measurement capabilities, the IAEA began implementing Co-ordinated Research Projects (CRPs) in 1992. The first project, entitled Isotope Variations of Carbon Dioxide and other Trace Gases in the Atmosphere, was implemented from 1992 to 1994. A significant contribution was made towards a better understanding of the global carbon cycle and especially of the sources and sinks of carbon with data on the {sup 14}C and {sup 13}C content of atmospheric CO{sub 2}, pointing to a better understanding of the problem of the 'missing sink' in the global carbon cycle. Important methodological developments in the field of high precision stable isotope mass spectrometry and improved data acquisition procedures emerged from work carried out within the framework of this programme. The development of pressurized gas standards and planning for an associated interlaboratory calibration were initiated. Due to the good progress and long standing nature of the required work a second CRP was initiated and implemented from 1996 to 1999. It was entitled Isotope aided Studies of Atmospheric Carbon Dioxide and Other Trace Gases - Phase II, to document the close relationship of both programmes. This publication provides an overview of the scientific outcomes of the